b633319 feat(drm): tearing page flips for scanned-out surfaces (wp_tearing_control_v1) and VRR · neferwl

M internal/adapters/config/config.go +14 -0


@@ -106,6 +106,8 @@ func Defaults() ports.Config {
106	106		c.Binds[move] = fmt.Sprintf("move-to-workspace %d", n)
107	107		}
108	108		c.Render.DirectScanout = true
	109	+	c.Render.Tearing = true
	110	+	c.Render.VRR = true
109	111		c.Log.Level = "info"
110	112		c.Log.Debug = []string{}
111	113		return c

@@ -451,6 +453,18 @@ func set(c *ports.Config, key, v string) error {
451	453		return err
452	454		}
453	455		c.Render.DirectScanout = b
	456	+	case "render.tearing":
	457	+	b, err := onOff(v)
	458	+	if err != nil {
	459	+	return err
	460	+	}
	461	+	c.Render.Tearing = b
	462	+	case "render.vrr":
	463	+	b, err := onOff(v)
	464	+	if err != nil {
	465	+	return err
	466	+	}
	467	+	c.Render.VRR = b
454	468		case "log.level":
455	469		if v != "debug" && v != "info" && v != "warn" && v != "error" {
456	470		return fmt.Errorf("must be debug, info, warn or error")


@@ -106,6 +106,8 @@ func Defaults() ports.Config {
106	c.Binds[move] = fmt.Sprintf("move-to-workspace %d", n)	106		c.Binds[move] = fmt.Sprintf("move-to-workspace %d", n)
107	}	107		}
108	c.Render.DirectScanout = true	108		c.Render.DirectScanout = true
		109	+	c.Render.Tearing = true
		110	+	c.Render.VRR = true
109	c.Log.Level = "info"	111		c.Log.Level = "info"
110	c.Log.Debug = []string{}	112		c.Log.Debug = []string{}
111	return c	113		return c

@@ -451,6 +453,18 @@ func set(c *ports.Config, key, v string) error {
451	return err	453		return err
452	}	454		}
453	c.Render.DirectScanout = b	455		c.Render.DirectScanout = b
		456	+	case "render.tearing":
		457	+	b, err := onOff(v)
		458	+	if err != nil {
		459	+	return err
		460	+	}
		461	+	c.Render.Tearing = b
		462	+	case "render.vrr":
		463	+	b, err := onOff(v)
		464	+	if err != nil {
		465	+	return err
		466	+	}
		467	+	c.Render.VRR = b
454	case "log.level":	468		case "log.level":
455	if v != "debug" && v != "info" && v != "warn" && v != "error" {	469		if v != "debug" && v != "info" && v != "warn" && v != "error" {
456	return fmt.Errorf("must be debug, info, warn or error")	470		return fmt.Errorf("must be debug, info, warn or error")

M internal/adapters/config/config_test.go +3 -1


@@ -62,6 +62,8 @@ output.DP-1.scale = 1.5
62	62		output.DP-1.primary = on
63	63		bind.cmd+code:30 = quit
64	64		render.direct-scanout = off
	65	+	render.tearing = off
	66	+	render.vrr = off
65	67		startup = wl-paste --watch cliphist store
66	68		startup = wl-paste --primary --watch cliphist store
67	69		`)

@@ -71,7 +73,7 @@ startup = wl-paste --primary --watch cliphist store
71	73		if !reflect.DeepEqual(c.Startup, [][]string{{"wl-paste", "--watch", "cliphist", "store"}, {"wl-paste", "--primary", "--watch", "cliphist", "store"}}) {
72	74		t.Fatalf("startup: %q", c.Startup)
73	75		}
74		-	if c.Keyboard.Layout != "fr" \|\| c.Keyboard.RepeatRate != 40 \|\| !reflect.DeepEqual(c.Terminal.Command, []string{"foot", "--server"}) \|\| c.Background.Color != "#000000" \|\| c.Render.DirectScanout {
	76	+	if c.Keyboard.Layout != "fr" \|\| c.Keyboard.RepeatRate != 40 \|\| !reflect.DeepEqual(c.Terminal.Command, []string{"foot", "--server"}) \|\| c.Background.Color != "#000000" \|\| c.Render.DirectScanout \|\| c.Render.Tearing \|\| c.Render.VRR {
75	77		t.Fatalf("%+v", c)
76	78		}
77	79		if !reflect.DeepEqual(c.Layout.Presets, []string{"1/3", "1/2", "1"}) \|\| !reflect.DeepEqual(c.Log.Debug, []string{"core", "input"}) {

 output.DP-1.primary = on
 bind.cmd+code:30 = quit
 render.direct-scanout = off
+render.tearing = off
+render.vrr = off
 startup = wl-paste --watch cliphist store
 startup = wl-paste --primary --watch cliphist store
 `)
 	if !reflect.DeepEqual(c.Startup, [][]string{{"wl-paste", "--watch", "cliphist", "store"}, {"wl-paste", "--primary", "--watch", "cliphist", "store"}}) {
 		t.Fatalf("startup: %q", c.Startup)
 	}
-	if c.Keyboard.Layout != "fr" || c.Keyboard.RepeatRate != 40 || !reflect.DeepEqual(c.Terminal.Command, []string{"foot", "--server"}) || c.Background.Color != "#000000" || c.Render.DirectScanout {
+	if c.Keyboard.Layout != "fr" || c.Keyboard.RepeatRate != 40 || !reflect.DeepEqual(c.Terminal.Command, []string{"foot", "--server"}) || c.Background.Color != "#000000" || c.Render.DirectScanout || c.Render.Tearing || c.Render.VRR {
 		t.Fatalf("%+v", c)
 	}
 	if !reflect.DeepEqual(c.Layout.Presets, []string{"1/3", "1/2", "1"}) || !reflect.DeepEqual(c.Log.Debug, []string{"core", "input"}) {

M internal/adapters/drm/card.go +5 -1


@@ -29,6 +29,8 @@ type Card struct {
29	29		// their own goroutines); modifiers is DRM_CAP_ADDFB2_MODIFIERS.
30	30		gemMu sync.Mutex
31	31		modifiers bool
	32	+	// async is DRM_CAP_ASYNC_PAGE_FLIP.
	33	+	async bool
32	34		}
33	35
34	36		// OpenCard reads the card's CRTCs. fd stays owned by the caller.

@@ -43,7 +45,9 @@ func OpenCard(fd int, path string, want Want, log zerowrap.Logger) (*Card, error
43	45		}
44	46		cp := getCap{capability: capAddFB2Modifiers}
45	47		mods := ioctl(fd, ioctlGetCap, unsafe.Pointer(&cp)) == nil && cp.value == 1
46		-	return &Card{fd: fd, path: path, want: want, log: log, crtcs: crtcs, outputs: map[string]*Output{}, flips: flips, modifiers: mods}, nil
	48	+	ap := getCap{capability: capAsyncPageFlip}
	49	+	async := ioctl(fd, ioctlGetCap, unsafe.Pointer(&ap)) == nil && ap.value == 1
	50	+	return &Card{fd: fd, path: path, want: want, log: log, crtcs: crtcs, outputs: map[string]*Output{}, flips: flips, modifiers: mods, async: async}, nil
47	51		}
48	52
49	53		// Path is the device path, e.g. /dev/dri/card1.

 	// their own goroutines); modifiers is DRM_CAP_ADDFB2_MODIFIERS.
 	gemMu     sync.Mutex
 	modifiers bool
+	// async is DRM_CAP_ASYNC_PAGE_FLIP.
+	async bool
 }
 // OpenCard reads the card's CRTCs. fd stays owned by the caller.
 	}
 	cp := getCap{capability: capAddFB2Modifiers}
 	mods := ioctl(fd, ioctlGetCap, unsafe.Pointer(&cp)) == nil && cp.value == 1
-	return &Card{fd: fd, path: path, want: want, log: log, crtcs: crtcs, outputs: map[string]*Output{}, flips: flips, modifiers: mods}, nil
+	ap := getCap{capability: capAsyncPageFlip}
+	async := ioctl(fd, ioctlGetCap, unsafe.Pointer(&ap)) == nil && ap.value == 1
+	return &Card{fd: fd, path: path, want: want, log: log, crtcs: crtcs, outputs: map[string]*Output{}, flips: flips, modifiers: mods, async: async}, nil
 }
 // Path is the device path, e.g. /dev/dri/card1.

M internal/adapters/drm/kms.go +9 -1


@@ -25,6 +25,7 @@ const (
25	25		ioctlDestroyDumb = 0xC00464B4
26	26
27	27		pageFlipEvent = 1
	28	+	pageFlipAsync = 2
28	29		eventFlipDone = 2
29	30		modeTypePrefered = 1 << 3
30	31		connected = 1

@@ -121,6 +122,10 @@ type Want struct {
121	122		Modes map[string][3]float64
122	123		// NoScanout disables direct scanout (render.direct-scanout = off).
123	124		NoScanout bool
	125	+	// NoTearing ignores tearing requests (render.tearing = off).
	126	+	NoTearing bool
	127	+	// NoVRR keeps variable refresh off (render.vrr = off).
	128	+	NoVRR bool
124	129		}
125	130
126	131		// usable reports whether a connector should be driven.

@@ -316,8 +321,11 @@ func getCrtc(fd int, crtc uint32) (modeCrtc, error) {
316	321		return c, err
317	322		}
318	323
319		-	func flip(fd int, crtc, fb uint32) error {
	324	+	func flip(fd int, crtc, fb uint32, async bool) error {
320	325		p := pageFlip{crtcID: crtc, fbID: fb, flags: pageFlipEvent}
	326	+	if async {
	327	+	p.flags \|= pageFlipAsync
	328	+	}
321	329		return ioctl(fd, ioctlPageFlip, unsafe.Pointer(&p))
322	330		}
323	331

 	ioctlDestroyDumb  = 0xC00464B4
 	pageFlipEvent    = 1
+	pageFlipAsync    = 2
 	eventFlipDone    = 2
 	modeTypePrefered = 1 << 3
 	connected        = 1
 	Modes map[string][3]float64
 	// NoScanout disables direct scanout (render.direct-scanout = off).
 	NoScanout bool
+	// NoTearing ignores tearing requests (render.tearing = off).
+	NoTearing bool
+	// NoVRR keeps variable refresh off (render.vrr = off).
+	NoVRR bool
 }
 // usable reports whether a connector should be driven.
 	return c, err
 }
-func flip(fd int, crtc, fb uint32) error {
+func flip(fd int, crtc, fb uint32, async bool) error {
 	p := pageFlip{crtcID: crtc, fbID: fb, flags: pageFlipEvent}
+	if async {
+		p.flags |= pageFlipAsync
+	}
 	return ioctl(fd, ioctlPageFlip, unsafe.Pointer(&p))
 }

M internal/adapters/drm/kms_test.go +3 -0


@@ -23,6 +23,9 @@ func TestStructSizesMatchIoctls(t *testing.T) {
23	23		{"fb_cmd2", unsafe.Sizeof(fbCmd2{}), ioctlAddFB2},
24	24		{"prime_handle", unsafe.Sizeof(primeHandle{}), ioctlPrimeFDToHandle},
25	25		{"gem_close", unsafe.Sizeof(gemClose{}), ioctlGemClose},
	26	+	{"obj_get_props", unsafe.Sizeof(objGetProps{}), ioctlObjGetProps},
	27	+	{"get_prop", unsafe.Sizeof(getProp{}), ioctlGetProp},
	28	+	{"obj_set_prop", unsafe.Sizeof(objSetProp{}), ioctlObjSetProp},
26	29		} {
27	30		if want := (tc.req >> 16) & 0x3fff; tc.got != want {
28	31		t.Errorf("%s: size %d, ioctl encodes %d", tc.name, tc.got, want)


@@ -23,6 +23,9 @@ func TestStructSizesMatchIoctls(t *testing.T) {
23	{"fb_cmd2", unsafe.Sizeof(fbCmd2{}), ioctlAddFB2},	23		{"fb_cmd2", unsafe.Sizeof(fbCmd2{}), ioctlAddFB2},
24	{"prime_handle", unsafe.Sizeof(primeHandle{}), ioctlPrimeFDToHandle},	24		{"prime_handle", unsafe.Sizeof(primeHandle{}), ioctlPrimeFDToHandle},
25	{"gem_close", unsafe.Sizeof(gemClose{}), ioctlGemClose},	25		{"gem_close", unsafe.Sizeof(gemClose{}), ioctlGemClose},
		26	+	{"obj_get_props", unsafe.Sizeof(objGetProps{}), ioctlObjGetProps},
		27	+	{"get_prop", unsafe.Sizeof(getProp{}), ioctlGetProp},
		28	+	{"obj_set_prop", unsafe.Sizeof(objSetProp{}), ioctlObjSetProp},
26	} {	29		} {
27	if want := (tc.req >> 16) & 0x3fff; tc.got != want {	30		if want := (tc.req >> 16) & 0x3fff; tc.got != want {
28	t.Errorf("%s: size %d, ioctl encodes %d", tc.name, tc.got, want)	31		t.Errorf("%s: size %d, ioctl encodes %d", tc.name, tc.got, want)

M internal/adapters/drm/output.go +57 -3


@@ -44,6 +44,12 @@ type Output struct {
44	44		shown, queued uint64
45	45		reason string // why the last frame was composed ("" = scanout)
46	46		unsent ports.OutputPresented
	47	+	// Tearing (ADR 006): async flips of scanned-out buffers that ask for
	48	+	// them, while the card accepts them. vrrProp is the CRTC's VRR_ENABLED
	49	+	// property (0: no VRR), turned on while a buffer is scanned out.
	50	+	tearing bool
	51	+	vrrProp uint32
	52	+	vrrOn, async bool
47	53		// kind is how the images were made; validated once a modeset took them.
48	54		kind imageKind
49	55		validated bool

@@ -61,10 +67,14 @@ func newOutput(card Card, c connector, mode modeInfo, crtc uint32) (Output, er
61	67		if o.saved, err = getCrtc(card.fd, crtc); err != nil {
62	68		log.Warn().Err(err).Uint32("crtc", crtc).Msg("save crtc; it will not be restored on exit")
63	69		}
	70	+	o.tearing = card.async && !card.want.NoTearing
	71	+	if !card.want.NoVRR {
	72	+	o.vrrProp = vrrProperty(card.fd, c.id, crtc)
	73	+	}
64	74		if o.cursor, err = newCursor(card.fd, crtc, slices.Index(card.crtcs, crtc)); err != nil {
65	75		log.Warn().Err(err).Str("connector", c.name).Msg("no hardware cursor")
66	76		}
67		-	log.Info().Str("card", card.path).Str("connector", c.name).Str("mode", mode.String()).Str("make", o.monitor.Make).Str("model", o.monitor.Model).Uint32("crtc", crtc).Msg("output")
	77	+	log.Info().Str("card", card.path).Str("connector", c.name).Str("mode", mode.String()).Str("make", o.monitor.Make).Str("model", o.monitor.Model).Uint32("crtc", crtc).Bool("tearing", o.tearing).Bool("vrr", o.vrrProp != 0).Msg("output")
68	78		return o, nil
69	79		}
70	80

@@ -93,6 +103,9 @@ func (o *Output) modeset() error {
93	103		return fmt.Errorf("set crtc: %w", err)
94	104		}
95	105		o.log.Info().Str("connector", o.conn.name).Msg("modeset")
	106	+	// Another master may have left VRR on: start from off.
	107	+	o.vrrOn = true
	108	+	o.setVRR(false)
96	109		return nil
97	110		}
98	111

@@ -102,7 +115,9 @@ func (o *Output) present(r ports.Renderer) error {
102	115		if b := o.bufs[o.back]; b != nil {
103	116		r.CopyBGRX(b.mem, int(b.pitch))
104	117		}
105		-	if err := flip(o.fd, o.crtc, o.fbs[o.back]); err != nil {
	118	+	o.setVRR(false)
	119	+	o.setAsync(false)
	120	+	if err := flip(o.fd, o.crtc, o.fbs[o.back], false); err != nil {
106	121		return err
107	122		}
108	123		o.pending, o.flipStart = true, time.Now()

@@ -134,7 +149,19 @@ func (o *Output) tryScanout(scene ports.Scene, surfaces map[ports.WindowID]ports
134	149		// Already on screen: nothing to flip.
135	150		return true, nil
136	151		}
137		-	if err := flip(o.fd, o.crtc, fb); err != nil {
	152	+	o.setVRR(true)
	153	+	// Drivers refuse async flips that change the format or modifier: the
	154	+	// flip from the composed image into scanout waits for vblank.
	155	+	async := c.Async && o.tearing && o.shown != 0
	156	+	o.setAsync(async)
	157	+	err := flip(o.fd, o.crtc, fb, async)
	158	+	if err != nil && async && errors.Is(err, unix.EINVAL) {
	159	+	// Refused anyway (e.g. the client changed buffer layout): flip
	160	+	// at vblank this time.
	161	+	o.log.Debug().Err(err).Str("connector", o.conn.name).Msg("async flip refused")
	162	+	err = flip(o.fd, o.crtc, fb, false)
	163	+	}
	164	+	if err != nil {
138	165		if errors.Is(err, unix.EINVAL) \|\| errors.Is(err, unix.ERANGE) {
139	166		// KMS refuses this buffer on the plane: compose it instead.
140	167		o.log.Info().Err(err).Uint32("format", c.DMABuf.Format).Uint64("modifier", c.DMABuf.Modifier).Msg("scanout flip refused")

@@ -150,12 +177,39 @@ func (o *Output) tryScanout(scene ports.Scene, surfaces map[ports.WindowID]ports
150	177		return true, nil
151	178		}
152	179
	180	+	// setVRR turns variable refresh on or off, when the output has it.
	181	+	func (o *Output) setVRR(on bool) {
	182	+	if o.vrrProp == 0 \|\| on == o.vrrOn {
	183	+	return
	184	+	}
	185	+	v := uint64(0)
	186	+	if on {
	187	+	v = 1
	188	+	}
	189	+	if err := setProp(o.fd, o.crtc, objCrtc, o.vrrProp, v); err != nil {
	190	+	o.log.Warn().Err(err).Str("connector", o.conn.name).Msg("vrr; disabled")
	191	+	o.vrrProp = 0
	192	+	return
	193	+	}
	194	+	o.vrrOn = on
	195	+	o.log.Info().Bool("vrr", on).Str("connector", o.conn.name).Msg("vrr")
	196	+	}
	197	+
	198	+	// setAsync logs when the output starts or stops tearing.
	199	+	func (o *Output) setAsync(on bool) {
	200	+	if on != o.async {
	201	+	o.async = on
	202	+	o.log.Info().Bool("tearing", on).Str("connector", o.conn.name).Msg("tearing")
	203	+	}
	204	+	}
	205	+
153	206		// Close restores the CRTC state found at startup, when it had a mode, and
154	207		// frees buffers.
155	208		func (o *Output) Close() {
156	209		if o.cursor != nil {
157	210		o.cursor.close()
158	211		}
	212	+	o.setVRR(false)
159	213		if o.saved.crtcID != 0 {
160	214		ids := []uint32{o.conn.id}
161	215		s := o.saved


@@ -44,6 +44,12 @@ type Output struct {
44		shown, queued uint64	44		shown, queued uint64
45		reason string // why the last frame was composed ("" = scanout)	45		reason string // why the last frame was composed ("" = scanout)
46		unsent ports.OutputPresented	46		unsent ports.OutputPresented
			47	+	// Tearing (ADR 006): async flips of scanned-out buffers that ask for
			48	+	// them, while the card accepts them. vrrProp is the CRTC's VRR_ENABLED
			49	+	// property (0: no VRR), turned on while a buffer is scanned out.
			50	+	tearing bool
			51	+	vrrProp uint32
			52	+	vrrOn, async bool
47		// kind is how the images were made; validated once a modeset took them.	53		// kind is how the images were made; validated once a modeset took them.
48		kind imageKind	54		kind imageKind
49		validated bool	55		validated bool

@@ -61,10 +67,14 @@ func newOutput(card Card, c connector, mode modeInfo, crtc uint32) (Output, er
61		if o.saved, err = getCrtc(card.fd, crtc); err != nil {	67		if o.saved, err = getCrtc(card.fd, crtc); err != nil {
62		log.Warn().Err(err).Uint32("crtc", crtc).Msg("save crtc; it will not be restored on exit")	68		log.Warn().Err(err).Uint32("crtc", crtc).Msg("save crtc; it will not be restored on exit")
63		}	69		}
			70	+	o.tearing = card.async && !card.want.NoTearing
			71	+	if !card.want.NoVRR {
			72	+	o.vrrProp = vrrProperty(card.fd, c.id, crtc)
			73	+	}
64		if o.cursor, err = newCursor(card.fd, crtc, slices.Index(card.crtcs, crtc)); err != nil {	74		if o.cursor, err = newCursor(card.fd, crtc, slices.Index(card.crtcs, crtc)); err != nil {
65		log.Warn().Err(err).Str("connector", c.name).Msg("no hardware cursor")	75		log.Warn().Err(err).Str("connector", c.name).Msg("no hardware cursor")
66		}	76		}
67	-	log.Info().Str("card", card.path).Str("connector", c.name).Str("mode", mode.String()).Str("make", o.monitor.Make).Str("model", o.monitor.Model).Uint32("crtc", crtc).Msg("output")	77	+	log.Info().Str("card", card.path).Str("connector", c.name).Str("mode", mode.String()).Str("make", o.monitor.Make).Str("model", o.monitor.Model).Uint32("crtc", crtc).Bool("tearing", o.tearing).Bool("vrr", o.vrrProp != 0).Msg("output")
68		return o, nil	78		return o, nil
69		}	79		}
70			80

@@ -93,6 +103,9 @@ func (o *Output) modeset() error {
93		return fmt.Errorf("set crtc: %w", err)	103		return fmt.Errorf("set crtc: %w", err)
94		}	104		}
95		o.log.Info().Str("connector", o.conn.name).Msg("modeset")	105		o.log.Info().Str("connector", o.conn.name).Msg("modeset")
			106	+	// Another master may have left VRR on: start from off.
			107	+	o.vrrOn = true
			108	+	o.setVRR(false)
96		return nil	109		return nil
97		}	110		}
98			111

@@ -102,7 +115,9 @@ func (o *Output) present(r ports.Renderer) error {
102		if b := o.bufs[o.back]; b != nil {	115		if b := o.bufs[o.back]; b != nil {
103		r.CopyBGRX(b.mem, int(b.pitch))	116		r.CopyBGRX(b.mem, int(b.pitch))
104		}	117		}
105	-	if err := flip(o.fd, o.crtc, o.fbs[o.back]); err != nil {	118	+	o.setVRR(false)
			119	+	o.setAsync(false)
			120	+	if err := flip(o.fd, o.crtc, o.fbs[o.back], false); err != nil {
106		return err	121		return err
107		}	122		}
108		o.pending, o.flipStart = true, time.Now()	123		o.pending, o.flipStart = true, time.Now()

@@ -134,7 +149,19 @@ func (o *Output) tryScanout(scene ports.Scene, surfaces map[ports.WindowID]ports
134		// Already on screen: nothing to flip.	149		// Already on screen: nothing to flip.
135		return true, nil	150		return true, nil
136		}	151		}
137	-	if err := flip(o.fd, o.crtc, fb); err != nil {	152	+	o.setVRR(true)
			153	+	// Drivers refuse async flips that change the format or modifier: the
			154	+	// flip from the composed image into scanout waits for vblank.
			155	+	async := c.Async && o.tearing && o.shown != 0
			156	+	o.setAsync(async)
			157	+	err := flip(o.fd, o.crtc, fb, async)
			158	+	if err != nil && async && errors.Is(err, unix.EINVAL) {
			159	+	// Refused anyway (e.g. the client changed buffer layout): flip
			160	+	// at vblank this time.
			161	+	o.log.Debug().Err(err).Str("connector", o.conn.name).Msg("async flip refused")
			162	+	err = flip(o.fd, o.crtc, fb, false)
			163	+	}
			164	+	if err != nil {
138		if errors.Is(err, unix.EINVAL) \|\| errors.Is(err, unix.ERANGE) {	165		if errors.Is(err, unix.EINVAL) \|\| errors.Is(err, unix.ERANGE) {
139		// KMS refuses this buffer on the plane: compose it instead.	166		// KMS refuses this buffer on the plane: compose it instead.
140		o.log.Info().Err(err).Uint32("format", c.DMABuf.Format).Uint64("modifier", c.DMABuf.Modifier).Msg("scanout flip refused")	167		o.log.Info().Err(err).Uint32("format", c.DMABuf.Format).Uint64("modifier", c.DMABuf.Modifier).Msg("scanout flip refused")

@@ -150,12 +177,39 @@ func (o *Output) tryScanout(scene ports.Scene, surfaces map[ports.WindowID]ports
150		return true, nil	177		return true, nil
151		}	178		}
152			179
			180	+	// setVRR turns variable refresh on or off, when the output has it.
			181	+	func (o *Output) setVRR(on bool) {
			182	+	if o.vrrProp == 0 \|\| on == o.vrrOn {
			183	+	return
			184	+	}
			185	+	v := uint64(0)
			186	+	if on {
			187	+	v = 1
			188	+	}
			189	+	if err := setProp(o.fd, o.crtc, objCrtc, o.vrrProp, v); err != nil {
			190	+	o.log.Warn().Err(err).Str("connector", o.conn.name).Msg("vrr; disabled")
			191	+	o.vrrProp = 0
			192	+	return
			193	+	}
			194	+	o.vrrOn = on
			195	+	o.log.Info().Bool("vrr", on).Str("connector", o.conn.name).Msg("vrr")
			196	+	}
			197	+
			198	+	// setAsync logs when the output starts or stops tearing.
			199	+	func (o *Output) setAsync(on bool) {
			200	+	if on != o.async {
			201	+	o.async = on
			202	+	o.log.Info().Bool("tearing", on).Str("connector", o.conn.name).Msg("tearing")
			203	+	}
			204	+	}
			205	+
153		// Close restores the CRTC state found at startup, when it had a mode, and	206		// Close restores the CRTC state found at startup, when it had a mode, and
154		// frees buffers.	207		// frees buffers.
155		func (o *Output) Close() {	208		func (o *Output) Close() {
156		if o.cursor != nil {	209		if o.cursor != nil {
157		o.cursor.close()	210		o.cursor.close()
158		}	211		}
			212	+	o.setVRR(false)
159		if o.saved.crtcID != 0 {	213		if o.saved.crtcID != 0 {
160		ids := []uint32{o.conn.id}	214		ids := []uint32{o.conn.id}
161		s := o.saved	215		s := o.saved

A internal/adapters/drm/props.go +82 -0

@@ -0,0 +1,82 @@
	1	+	package drm
	2	+
	3	+	import (
	4	+	"unsafe"
	5	+
	6	+	"golang.org/x/sys/unix"
	7	+	)
	8	+
	9	+	// KMS object properties, read and set with the legacy property ioctls.
	10	+
	11	+	const (
	12	+	ioctlObjGetProps = 0xC02064B9 // DRM_IOWR('d', 0xB9, struct drm_mode_obj_get_properties)
	13	+	ioctlGetProp = 0xC04064AA // DRM_IOWR('d', 0xAA, struct drm_mode_get_property)
	14	+	ioctlObjSetProp = 0xC01864BA // DRM_IOWR('d', 0xBA, struct drm_mode_obj_set_property)
	15	+
	16	+	objCrtc = 0xcccccccc
	17	+	objConnector = 0xc0c0c0c0
	18	+	)
	19	+
	20	+	type objGetProps struct {
	21	+	props, values uint64
	22	+	count, objID uint32
	23	+	objType, _ uint32
	24	+	}
	25	+
	26	+	type getProp struct {
	27	+	values, enumBlobs uint64
	28	+	propID, flags uint32
	29	+	name [32]byte
	30	+	countValues, countEn uint32
	31	+	}
	32	+
	33	+	type objSetProp struct {
	34	+	value uint64
	35	+	propID, objID, objType uint32
	36	+	_ uint32
	37	+	}
	38	+
	39	+	// objProps returns an object's property IDs and values by name.
	40	+	func objProps(fd int, obj, typ uint32) (map[string][2]uint64, error) {
	41	+	q := objGetProps{objID: obj, objType: typ}
	42	+	if err := ioctl(fd, ioctlObjGetProps, unsafe.Pointer(&q)); err != nil {
	43	+	return nil, err
	44	+	}
	45	+	out := map[string][2]uint64{}
	46	+	if q.count == 0 {
	47	+	return out, nil
	48	+	}
	49	+	ids := make([]uint32, q.count)
	50	+	vals := make([]uint64, q.count)
	51	+	q.props, q.values = uint64(uintptr(unsafe.Pointer(&ids[0]))), uint64(uintptr(unsafe.Pointer(&vals[0])))
	52	+	if err := ioctl(fd, ioctlObjGetProps, unsafe.Pointer(&q)); err != nil {
	53	+	return nil, err
	54	+	}
	55	+	for i := range min(int(q.count), len(ids)) {
	56	+	p := getProp{propID: ids[i]}
	57	+	if ioctl(fd, ioctlGetProp, unsafe.Pointer(&p)) != nil {
	58	+	continue
	59	+	}
	60	+	out[unix.ByteSliceToString(p.name[:])] = [2]uint64{uint64(ids[i]), vals[i]}
	61	+	}
	62	+	return out, nil
	63	+	}
	64	+
	65	+	// vrrProperty returns the CRTC's VRR_ENABLED property when the connector
	66	+	// is VRR capable, else 0.
	67	+	func vrrProperty(fd int, conn, crtc uint32) uint32 {
	68	+	cp, err := objProps(fd, conn, objConnector)
	69	+	if err != nil \|\| cp["vrr_capable"][1] != 1 {
	70	+	return 0
	71	+	}
	72	+	rp, err := objProps(fd, crtc, objCrtc)
	73	+	if err != nil {
	74	+	return 0
	75	+	}
	76	+	return uint32(rp["VRR_ENABLED"][0])
	77	+	}
	78	+
	79	+	func setProp(fd int, obj, typ, prop uint32, v uint64) error {
	80	+	s := objSetProp{value: v, propID: prop, objID: obj, objType: typ}
	81	+	return ioctl(fd, ioctlObjSetProp, unsafe.Pointer(&s))
	82	+	}

@@ -0,0 +1,82 @@
	1	+	package drm
	2	+
	3	+	import (
	4	+	"unsafe"
	5	+
	6	+	"golang.org/x/sys/unix"
	7	+	)
	8	+
	9	+	// KMS object properties, read and set with the legacy property ioctls.
	10	+
	11	+	const (
	12	+	ioctlObjGetProps = 0xC02064B9 // DRM_IOWR('d', 0xB9, struct drm_mode_obj_get_properties)
	13	+	ioctlGetProp = 0xC04064AA // DRM_IOWR('d', 0xAA, struct drm_mode_get_property)
	14	+	ioctlObjSetProp = 0xC01864BA // DRM_IOWR('d', 0xBA, struct drm_mode_obj_set_property)
	15	+
	16	+	objCrtc = 0xcccccccc
	17	+	objConnector = 0xc0c0c0c0
	18	+	)
	19	+
	20	+	type objGetProps struct {
	21	+	props, values uint64
	22	+	count, objID uint32
	23	+	objType, _ uint32
	24	+	}
	25	+
	26	+	type getProp struct {
	27	+	values, enumBlobs uint64
	28	+	propID, flags uint32
	29	+	name [32]byte
	30	+	countValues, countEn uint32
	31	+	}
	32	+
	33	+	type objSetProp struct {
	34	+	value uint64
	35	+	propID, objID, objType uint32
	36	+	_ uint32
	37	+	}
	38	+
	39	+	// objProps returns an object's property IDs and values by name.
	40	+	func objProps(fd int, obj, typ uint32) (map[string][2]uint64, error) {
	41	+	q := objGetProps{objID: obj, objType: typ}
	42	+	if err := ioctl(fd, ioctlObjGetProps, unsafe.Pointer(&q)); err != nil {
	43	+	return nil, err
	44	+	}
	45	+	out := map[string][2]uint64{}
	46	+	if q.count == 0 {
	47	+	return out, nil
	48	+	}
	49	+	ids := make([]uint32, q.count)
	50	+	vals := make([]uint64, q.count)
	51	+	q.props, q.values = uint64(uintptr(unsafe.Pointer(&ids[0]))), uint64(uintptr(unsafe.Pointer(&vals[0])))
	52	+	if err := ioctl(fd, ioctlObjGetProps, unsafe.Pointer(&q)); err != nil {
	53	+	return nil, err
	54	+	}
	55	+	for i := range min(int(q.count), len(ids)) {
	56	+	p := getProp{propID: ids[i]}
	57	+	if ioctl(fd, ioctlGetProp, unsafe.Pointer(&p)) != nil {
	58	+	continue
	59	+	}
	60	+	out[unix.ByteSliceToString(p.name[:])] = [2]uint64{uint64(ids[i]), vals[i]}
	61	+	}
	62	+	return out, nil
	63	+	}
	64	+
	65	+	// vrrProperty returns the CRTC's VRR_ENABLED property when the connector
	66	+	// is VRR capable, else 0.
	67	+	func vrrProperty(fd int, conn, crtc uint32) uint32 {
	68	+	cp, err := objProps(fd, conn, objConnector)
	69	+	if err != nil \|\| cp["vrr_capable"][1] != 1 {
	70	+	return 0
	71	+	}
	72	+	rp, err := objProps(fd, crtc, objCrtc)
	73	+	if err != nil {
	74	+	return 0
	75	+	}
	76	+	return uint32(rp["VRR_ENABLED"][0])
	77	+	}
	78	+
	79	+	func setProp(fd int, obj, typ, prop uint32, v uint64) error {
	80	+	s := objSetProp{value: v, propID: prop, objID: obj, objType: typ}
	81	+	return ioctl(fd, ioctlObjSetProp, unsafe.Pointer(&s))
	82	+	}

M internal/adapters/drm/scanout.go +1 -0


@@ -23,6 +23,7 @@ const (
23	23
24	24		fbModifiers = 1 << 1
25	25		capAddFB2Modifiers = 0x10
	26	+	capAsyncPageFlip = 0x7
26	27		modInvalid = 0x00ffffffffffffff
27	28		scanoutIdleTTL = 5 * time.Second // a cached framebuffer survives unused
28	29		)


@@ -23,6 +23,7 @@ const (
23		23
24	fbModifiers = 1 << 1	24		fbModifiers = 1 << 1
25	capAddFB2Modifiers = 0x10	25		capAddFB2Modifiers = 0x10
		26	+	capAsyncPageFlip = 0x7
26	modInvalid = 0x00ffffffffffffff	27		modInvalid = 0x00ffffffffffffff
27	scanoutIdleTTL = 5 * time.Second // a cached framebuffer survives unused	28		scanoutIdleTTL = 5 * time.Second // a cached framebuffer survives unused
28	)	29		)

M internal/adapters/wayland/globals.go +1 -0


@@ -17,6 +17,7 @@ func registerGlobals(d server.Display, o Options, s Server) error {
17	17		func() error { return registerCursorShape(d, s) },
18	18		func() error { return registerDMABuf(d, s, o.DMABuf) },
19	19		func() error { return registerPointerConstraints(d, s) },
	20	+	func() error { return registerTearing(d, s) },
20	21		func() error {
21	22		return wayland.NewCompositorGlobal(d, 6, func(c server.Client, v, id uint32) { wayland.NewCompositor(c, int32(v), id, compositor{s}) })
22	23		},


@@ -17,6 +17,7 @@ func registerGlobals(d server.Display, o Options, s Server) error {
17	func() error { return registerCursorShape(d, s) },	17		func() error { return registerCursorShape(d, s) },
18	func() error { return registerDMABuf(d, s, o.DMABuf) },	18		func() error { return registerDMABuf(d, s, o.DMABuf) },
19	func() error { return registerPointerConstraints(d, s) },	19		func() error { return registerPointerConstraints(d, s) },
		20	+	func() error { return registerTearing(d, s) },
20	func() error {	21		func() error {
21	return wayland.NewCompositorGlobal(d, 6, func(c server.Client, v, id uint32) { wayland.NewCompositor(c, int32(v), id, compositor{s}) })	22		return wayland.NewCompositorGlobal(d, 6, func(c server.Client, v, id uint32) { wayland.NewCompositor(c, int32(v), id, compositor{s}) })
22	},	23		},

M internal/adapters/wayland/surface.go +8 -1


@@ -42,6 +42,10 @@ type surface struct {
42	42		content ports.SurfaceContent
43	43		has bool
44	44		sub subState
	45	+	// tearing is the surface's wp_tearing_control_v1; async is the
	46	+	// committed hint, pendingAsync the requested one.
	47	+	tearing *tearingHandler
	48	+	async, pendingAsync bool
45	49		}
46	50
47	51		// subState is the subsurface tree: parent is set on subsurfaces, children

@@ -87,6 +91,7 @@ func (s *surface) tree(id ports.WindowID) ports.SurfaceContent {
87	91		if s.xdg != nil {
88	92		c.Geometry = s.xdg.geometry
89	93		}
	94	+	c.Async = s.async
90	95		return c
91	96		}
92	97

@@ -184,6 +189,8 @@ func (s surface) Commit(wayland.Surface) {
184	189		if s.pendingScale > 0 {
185	190		s.bufferScale = s.pendingScale
186	191		}
	192	+	hinted := s.async != s.pendingAsync
	193	+	s.async = s.pendingAsync
187	194		if s.viewport != nil {
188	195		s.viewport.commit()
189	196		}

@@ -237,7 +244,7 @@ func (s surface) Commit(wayland.Surface) {
237	244		if s.xdg != nil && s.xdg.window != nil {
238	245		s.xdg.window.afterCommit()
239	246		}
240		-	if fresh \|\| moved \|\| geometry \|\| s.sub.parent != nil {
	247	+	if fresh \|\| moved \|\| geometry \|\| hinted \|\| s.sub.parent != nil {
241	248		s.redraw()
242	249		}
243	250		}

 	content ports.SurfaceContent
 	has     bool
 	sub     subState
+	// tearing is the surface's wp_tearing_control_v1; async is the
+	// committed hint, pendingAsync the requested one.
+	tearing             *tearingHandler
+	async, pendingAsync bool
 }
 // subState is the subsurface tree: parent is set on subsurfaces, children
 	if s.xdg != nil {
 		c.Geometry = s.xdg.geometry
 	}
+	c.Async = s.async
 	return c
 }
 	if s.pendingScale > 0 {
 		s.bufferScale = s.pendingScale
 	}
+	hinted := s.async != s.pendingAsync
+	s.async = s.pendingAsync
 	if s.viewport != nil {
 		s.viewport.commit()
 	}
 	if s.xdg != nil && s.xdg.window != nil {
 		s.xdg.window.afterCommit()
 	}
-	if fresh || moved || geometry || s.sub.parent != nil {
+	if fresh || moved || geometry || hinted || s.sub.parent != nil {
 		s.redraw()
 	}
 }

A internal/adapters/wayland/tearing.go +55 -0

@@ -0,0 +1,55 @@
	1	+	package wayland
	2	+
	3	+	import (
	4	+	"github.com/bnema/purego-libwayland/protocol/tearingcontrol"
	5	+	"github.com/bnema/purego-libwayland/protocol/wayland"
	6	+	"github.com/bnema/purego-libwayland/server"
	7	+	)
	8	+
	9	+	// Tearing control: a surface asks for async presentation. Outputs honour it
	10	+	// only when they scan the surface out directly (ADR 006); the hint is
	11	+	// double-buffered state applied on commit.
	12	+
	13	+	func registerTearing(d server.Display, s Server) error {
	14	+	return tearingcontrol.NewWpTearingControlManagerV1Global(d, 1, func(c server.Client, v, id uint32) {
	15	+	_, _ = tearingcontrol.NewWpTearingControlManagerV1(c, int32(v), id, tearingManager{s})
	16	+	})
	17	+	}
	18	+
	19	+	type tearingManager struct{ server *Server }
	20	+
	21	+	func (tearingManager) Destroy(*tearingcontrol.WpTearingControlManagerV1) {}
	22	+
	23	+	func (m tearingManager) GetTearingControl(r tearingcontrol.WpTearingControlManagerV1, id uint32, surf wayland.Surface) {
	24	+	var state *surface
	25	+	if surf != nil {
	26	+	state = m.server.surfaces[surf.Resource]
	27	+	}
	28	+	if state != nil && state.tearing != nil {
	29	+	r.PostError(uint32(tearingcontrol.WpTearingControlManagerV1ErrorTearingControlExists), "surface already has a tearing control")
	30	+	return
	31	+	}
	32	+	h := &tearingHandler{surface: state}
	33	+	res, err := tearingcontrol.NewWpTearingControlV1(r.Client(), r.Version(), id, h)
	34	+	if err != nil \|\| state == nil {
	35	+	return
	36	+	}
	37	+	state.tearing = h
	38	+	res.OnDestroy = func() {
	39	+	// Back to vsync on the next commit.
	40	+	if state.tearing == h {
	41	+	state.tearing = nil
	42	+	state.pendingAsync = false
	43	+	}
	44	+	}
	45	+	}
	46	+
	47	+	type tearingHandler struct{ surface *surface }
	48	+
	49	+	func (h tearingHandler) SetPresentationHint(_ tearingcontrol.WpTearingControlV1, hint uint32) {
	50	+	if h.surface != nil && h.surface.tearing == h {
	51	+	h.surface.pendingAsync = hint == uint32(tearingcontrol.WpTearingControlV1PresentationHintAsync)
	52	+	}
	53	+	}
	54	+
	55	+	func (tearingHandler) Destroy(tearingcontrol.WpTearingControlV1) {}

@@ -0,0 +1,55 @@
	1	+	package wayland
	2	+
	3	+	import (
	4	+	"github.com/bnema/purego-libwayland/protocol/tearingcontrol"
	5	+	"github.com/bnema/purego-libwayland/protocol/wayland"
	6	+	"github.com/bnema/purego-libwayland/server"
	7	+	)
	8	+
	9	+	// Tearing control: a surface asks for async presentation. Outputs honour it
	10	+	// only when they scan the surface out directly (ADR 006); the hint is
	11	+	// double-buffered state applied on commit.
	12	+
	13	+	func registerTearing(d server.Display, s Server) error {
	14	+	return tearingcontrol.NewWpTearingControlManagerV1Global(d, 1, func(c server.Client, v, id uint32) {
	15	+	_, _ = tearingcontrol.NewWpTearingControlManagerV1(c, int32(v), id, tearingManager{s})
	16	+	})
	17	+	}
	18	+
	19	+	type tearingManager struct{ server *Server }
	20	+
	21	+	func (tearingManager) Destroy(*tearingcontrol.WpTearingControlManagerV1) {}
	22	+
	23	+	func (m tearingManager) GetTearingControl(r tearingcontrol.WpTearingControlManagerV1, id uint32, surf wayland.Surface) {
	24	+	var state *surface
	25	+	if surf != nil {
	26	+	state = m.server.surfaces[surf.Resource]
	27	+	}
	28	+	if state != nil && state.tearing != nil {
	29	+	r.PostError(uint32(tearingcontrol.WpTearingControlManagerV1ErrorTearingControlExists), "surface already has a tearing control")
	30	+	return
	31	+	}
	32	+	h := &tearingHandler{surface: state}
	33	+	res, err := tearingcontrol.NewWpTearingControlV1(r.Client(), r.Version(), id, h)
	34	+	if err != nil \|\| state == nil {
	35	+	return
	36	+	}
	37	+	state.tearing = h
	38	+	res.OnDestroy = func() {
	39	+	// Back to vsync on the next commit.
	40	+	if state.tearing == h {
	41	+	state.tearing = nil
	42	+	state.pendingAsync = false
	43	+	}
	44	+	}
	45	+	}
	46	+
	47	+	type tearingHandler struct{ surface *surface }
	48	+
	49	+	func (h tearingHandler) SetPresentationHint(_ tearingcontrol.WpTearingControlV1, hint uint32) {
	50	+	if h.surface != nil && h.surface.tearing == h {
	51	+	h.surface.pendingAsync = hint == uint32(tearingcontrol.WpTearingControlV1PresentationHintAsync)
	52	+	}
	53	+	}
	54	+
	55	+	func (tearingHandler) Destroy(tearingcontrol.WpTearingControlV1) {}

A internal/adapters/wayland/tearing_test.go +58 -0

@@ -0,0 +1,58 @@
	1	+	package wayland
	2	+
	3	+	import (
	4	+	"testing"
	5	+	"time"
	6	+
	7	+	"github.com/bnema/nefertty/internal/ports"
	8	+	"github.com/bnema/purego-libwayland/protocol/tearingcontrol"
	9	+	"github.com/bnema/purego-libwayland/protocol/wayland"
	10	+	)
	11	+
	12	+	// asyncContent waits for a content of window id with the given hint.
	13	+	func asyncContent(t *testing.T, contents <-chan ports.SurfaceContent, id ports.WindowID, async bool) {
	14	+	t.Helper()
	15	+	deadline := time.After(2 * time.Second)
	16	+	for {
	17	+	select {
	18	+	case c := <-contents:
	19	+	if c.ID == id && c.Async == async {
	20	+	return
	21	+	}
	22	+	case <-deadline:
	23	+	t.Fatalf("no content with async=%v", async)
	24	+	}
	25	+	}
	26	+	}
	27	+
	28	+	func TestTearingHintAppliesOnCommit(t *testing.T) {
	29	+	s, events, _, contents, dir := contentServer(t)
	30	+	c := protocolClient(t, s, dir)
	31	+	w, surf, _ := surfaceMapper(t, c, events)()
	32	+	manager := bindProtocol(t, c, "wp_tearing_control_manager_v1")
	33	+	control := c.AllocateID()
	34	+	registerProtocol(t, c, control)
	35	+	requestProtocol(t, c, manager, tearingcontrol.WpTearingControlManagerV1RequestGetTearingControl, control, surf)
	36	+	requestProtocol(t, c, control, tearingcontrol.WpTearingControlV1RequestSetPresentationHint, uint32(tearingcontrol.WpTearingControlV1PresentationHintAsync))
	37	+	requestProtocol(t, c, surf, wayland.SurfaceRequestCommit)
	38	+	if err := c.Roundtrip(); err != nil {
	39	+	t.Fatal(err)
	40	+	}
	41	+	asyncContent(t, contents, w.ID, true)
	42	+
	43	+	// Destroying the control goes back to vsync on the next commit.
	44	+	requestProtocol(t, c, control, tearingcontrol.WpTearingControlV1RequestDestroy)
	45	+	requestProtocol(t, c, surf, wayland.SurfaceRequestCommit)
	46	+	if err := c.Roundtrip(); err != nil {
	47	+	t.Fatal(err)
	48	+	}
	49	+	asyncContent(t, contents, w.ID, false)
	50	+
	51	+	// A surface has at most one control.
	52	+	first, second := c.AllocateID(), c.AllocateID()
	53	+	registerProtocol(t, c, first)
	54	+	registerProtocol(t, c, second)
	55	+	requestProtocol(t, c, manager, tearingcontrol.WpTearingControlManagerV1RequestGetTearingControl, first, surf)
	56	+	requestProtocol(t, c, manager, tearingcontrol.WpTearingControlManagerV1RequestGetTearingControl, second, surf)
	57	+	expectProtocolError(t, c, manager, uint32(tearingcontrol.WpTearingControlManagerV1ErrorTearingControlExists))
	58	+	}

@@ -0,0 +1,58 @@
	1	+	package wayland
	2	+
	3	+	import (
	4	+	"testing"
	5	+	"time"
	6	+
	7	+	"github.com/bnema/nefertty/internal/ports"
	8	+	"github.com/bnema/purego-libwayland/protocol/tearingcontrol"
	9	+	"github.com/bnema/purego-libwayland/protocol/wayland"
	10	+	)
	11	+
	12	+	// asyncContent waits for a content of window id with the given hint.
	13	+	func asyncContent(t *testing.T, contents <-chan ports.SurfaceContent, id ports.WindowID, async bool) {
	14	+	t.Helper()
	15	+	deadline := time.After(2 * time.Second)
	16	+	for {
	17	+	select {
	18	+	case c := <-contents:
	19	+	if c.ID == id && c.Async == async {
	20	+	return
	21	+	}
	22	+	case <-deadline:
	23	+	t.Fatalf("no content with async=%v", async)
	24	+	}
	25	+	}
	26	+	}
	27	+
	28	+	func TestTearingHintAppliesOnCommit(t *testing.T) {
	29	+	s, events, _, contents, dir := contentServer(t)
	30	+	c := protocolClient(t, s, dir)
	31	+	w, surf, _ := surfaceMapper(t, c, events)()
	32	+	manager := bindProtocol(t, c, "wp_tearing_control_manager_v1")
	33	+	control := c.AllocateID()
	34	+	registerProtocol(t, c, control)
	35	+	requestProtocol(t, c, manager, tearingcontrol.WpTearingControlManagerV1RequestGetTearingControl, control, surf)
	36	+	requestProtocol(t, c, control, tearingcontrol.WpTearingControlV1RequestSetPresentationHint, uint32(tearingcontrol.WpTearingControlV1PresentationHintAsync))
	37	+	requestProtocol(t, c, surf, wayland.SurfaceRequestCommit)
	38	+	if err := c.Roundtrip(); err != nil {
	39	+	t.Fatal(err)
	40	+	}
	41	+	asyncContent(t, contents, w.ID, true)
	42	+
	43	+	// Destroying the control goes back to vsync on the next commit.
	44	+	requestProtocol(t, c, control, tearingcontrol.WpTearingControlV1RequestDestroy)
	45	+	requestProtocol(t, c, surf, wayland.SurfaceRequestCommit)
	46	+	if err := c.Roundtrip(); err != nil {
	47	+	t.Fatal(err)
	48	+	}
	49	+	asyncContent(t, contents, w.ID, false)
	50	+
	51	+	// A surface has at most one control.
	52	+	first, second := c.AllocateID(), c.AllocateID()
	53	+	registerProtocol(t, c, first)
	54	+	registerProtocol(t, c, second)
	55	+	requestProtocol(t, c, manager, tearingcontrol.WpTearingControlManagerV1RequestGetTearingControl, first, surf)
	56	+	requestProtocol(t, c, manager, tearingcontrol.WpTearingControlManagerV1RequestGetTearingControl, second, surf)
	57	+	expectProtocolError(t, c, manager, uint32(tearingcontrol.WpTearingControlManagerV1ErrorTearingControlExists))
	58	+	}

M internal/app/app.go +2 -2


@@ -64,7 +64,7 @@ func run(ctx context.Context, opts Options, inject func(chan<- ports.InputEvent)
64	64		var hw *drmBackend
65	65		if opts.Backend == "drm" {
66	66		var err error
67		-	if hw, err = openDRM(ctx, opts.Config.Outputs, opts.Config.Render.DirectScanout); err != nil {
	67	+	if hw, err = openDRM(ctx, opts.Config); err != nil {
68	68		return err
69	69		}
70	70		defer hw.close()

@@ -208,7 +208,7 @@ func run(ctx context.Context, opts Options, inject func(chan<- ports.InputEvent)
208	208		}
209	209		if hw != nil {
210	210		done <- safe("output", func() error {
211		-	want := func() drm.Want { return wantFromConfig(opts.Config.Outputs, opts.Config.Render.DirectScanout) }
	211	+	want := func() drm.Want { return wantFromConfig(opts.Config) }
212	212		return hw.runOutputs(ctx, want, output, renderScenes, contents, cursorChanges, presented, curs, newRenderer, logging.For(ctx, "drm"))
213	213		})
214	214		return


@@ -64,7 +64,7 @@ func run(ctx context.Context, opts Options, inject func(chan<- ports.InputEvent)
64		var hw *drmBackend	64		var hw *drmBackend
65		if opts.Backend == "drm" {	65		if opts.Backend == "drm" {
66		var err error	66		var err error
67	-	if hw, err = openDRM(ctx, opts.Config.Outputs, opts.Config.Render.DirectScanout); err != nil {	67	+	if hw, err = openDRM(ctx, opts.Config); err != nil {
68		return err	68		return err
69		}	69		}
70		defer hw.close()	70		defer hw.close()

@@ -208,7 +208,7 @@ func run(ctx context.Context, opts Options, inject func(chan<- ports.InputEvent)
208		}	208		}
209		if hw != nil {	209		if hw != nil {
210		done <- safe("output", func() error {	210		done <- safe("output", func() error {
211	-	want := func() drm.Want { return wantFromConfig(opts.Config.Outputs, opts.Config.Render.DirectScanout) }	211	+	want := func() drm.Want { return wantFromConfig(opts.Config) }
212		return hw.runOutputs(ctx, want, output, renderScenes, contents, cursorChanges, presented, curs, newRenderer, logging.For(ctx, "drm"))	212		return hw.runOutputs(ctx, want, output, renderScenes, contents, cursorChanges, presented, curs, newRenderer, logging.For(ctx, "drm"))
213		})	213		})
214		return	214		return

M internal/app/drm.go +7 -6


@@ -42,14 +42,14 @@ func safe(name string, fn func() error) (err error) {
42	42
43	43		// openDRM opens the seat and every card with a connected display. Outputs
44	44		// are found by the first Scan of each card.
45		-	func openDRM(ctx context.Context, outputs []ports.OutputConfig, scanout bool) (*drmBackend, error) {
	45	+	func openDRM(ctx context.Context, cfg ports.Config) (*drmBackend, error) {
46	46		log := logging.For(ctx, "drm")
47	47		s, err := seat.Open(ctx, logging.For(ctx, "seat"))
48	48		if err != nil {
49	49		log.Error().Err(err).Msg("open seat")
50	50		return nil, fmt.Errorf("open seat: %w", err)
51	51		}
52		-	want := wantFromConfig(outputs, scanout)
	52	+	want := wantFromConfig(cfg)
53	53		paths, _ := filepath.Glob("/dev/dri/card[0-9]*")
54	54		sort.Strings(paths)
55	55		b := &drmBackend{seat: s}

@@ -78,10 +78,11 @@ func openDRM(ctx context.Context, outputs []ports.OutputConfig, scanout bool) (*
78	78		return b, nil
79	79		}
80	80
81		-	// wantFromConfig turns output.<name> entries into connector choices.
82		-	func wantFromConfig(outputs []ports.OutputConfig, scanout bool) drm.Want {
83		-	want := drm.Want{Disabled: map[string]bool{}, Modes: map[string][3]float64{}, NoScanout: !scanout}
84		-	for _, o := range outputs {
	81	+	// wantFromConfig turns output.<name> and render.* entries into connector choices.
	82	+	func wantFromConfig(cfg ports.Config) drm.Want {
	83	+	r := cfg.Render
	84	+	want := drm.Want{Disabled: map[string]bool{}, Modes: map[string][3]float64{}, NoScanout: !r.DirectScanout, NoTearing: !r.Tearing, NoVRR: !r.VRR}
	85	+	for _, o := range cfg.Outputs {
85	86		if o.Off {
86	87		want.Disabled[o.Name] = true
87	88		continue

 // openDRM opens the seat and every card with a connected display. Outputs
 // are found by the first Scan of each card.
-func openDRM(ctx context.Context, outputs []ports.OutputConfig, scanout bool) (*drmBackend, error) {
+func openDRM(ctx context.Context, cfg ports.Config) (*drmBackend, error) {
 	log := logging.For(ctx, "drm")
 	s, err := seat.Open(ctx, logging.For(ctx, "seat"))
 	if err != nil {
 		log.Error().Err(err).Msg("open seat")
 		return nil, fmt.Errorf("open seat: %w", err)
 	}
-	want := wantFromConfig(outputs, scanout)
+	want := wantFromConfig(cfg)
 	paths, _ := filepath.Glob("/dev/dri/card[0-9]*")
 	sort.Strings(paths)
 	b := &drmBackend{seat: s}
 	return b, nil
 }
-// wantFromConfig turns output.<name> entries into connector choices.
+// wantFromConfig turns output.<name> and render.* entries into connector choices.
-func wantFromConfig(outputs []ports.OutputConfig, scanout bool) drm.Want {
+func wantFromConfig(cfg ports.Config) drm.Want {
-	want := drm.Want{Disabled: map[string]bool{}, Modes: map[string][3]float64{}, NoScanout: !scanout}
+	r := cfg.Render
-	for _, o := range outputs {
+	want := drm.Want{Disabled: map[string]bool{}, Modes: map[string][3]float64{}, NoScanout: !r.DirectScanout, NoTearing: !r.Tearing, NoVRR: !r.VRR}
+	for _, o := range cfg.Outputs {
 		if o.Off {
 			want.Disabled[o.Name] = true
 			continue

M internal/app/drm_test.go +4 -2


@@ -7,8 +7,10 @@ import (
7	7		)
8	8
9	9		func TestWantFromConfig(t *testing.T) {
10		-	want := wantFromConfig([]ports.OutputConfig{{Name: "eDP-1", Scale: 2, ScaleOnly: true}, {Name: "HDMI-A-1", Mode: "1920x1080@60"}, {Name: "DP-3", Off: true}}, true)
11		-	if m := want.Modes["HDMI-A-1"]; m != [3]float64{1920, 1080, 60} \|\| !want.Disabled["DP-3"] \|\| len(want.Modes) != 1 {
	10	+	cfg := ports.Config{Outputs: []ports.OutputConfig{{Name: "eDP-1", Scale: 2, ScaleOnly: true}, {Name: "HDMI-A-1", Mode: "1920x1080@60"}, {Name: "DP-3", Off: true}}}
	11	+	cfg.Render.DirectScanout, cfg.Render.VRR = true, true
	12	+	want := wantFromConfig(cfg)
	13	+	if m := want.Modes["HDMI-A-1"]; m != [3]float64{1920, 1080, 60} \|\| !want.Disabled["DP-3"] \|\| len(want.Modes) != 1 \|\| want.NoScanout \|\| !want.NoTearing \|\| want.NoVRR {
12	14		t.Fatalf("%+v", want)
13	15		}
14	16		}

 )
 func TestWantFromConfig(t *testing.T) {
-	want := wantFromConfig([]ports.OutputConfig{{Name: "eDP-1", Scale: 2, ScaleOnly: true}, {Name: "HDMI-A-1", Mode: "1920x1080@60"}, {Name: "DP-3", Off: true}}, true)
+	cfg := ports.Config{Outputs: []ports.OutputConfig{{Name: "eDP-1", Scale: 2, ScaleOnly: true}, {Name: "HDMI-A-1", Mode: "1920x1080@60"}, {Name: "DP-3", Off: true}}}
-	if m := want.Modes["HDMI-A-1"]; m != [3]float64{1920, 1080, 60} || !want.Disabled["DP-3"] || len(want.Modes) != 1 {
+	cfg.Render.DirectScanout, cfg.Render.VRR = true, true
+	want := wantFromConfig(cfg)
+	if m := want.Modes["HDMI-A-1"]; m != [3]float64{1920, 1080, 60} || !want.Disabled["DP-3"] || len(want.Modes) != 1 || want.NoScanout || !want.NoTearing || want.NoVRR {
 		t.Fatalf("%+v", want)
 	}
 }

M internal/ports/config.go +3 -0


@@ -55,6 +55,9 @@ type Config struct {
55	55		Binds map[string]string
56	56		Render struct {
57	57		DirectScanout bool
	58	+	// Tearing honours wp_tearing_control_v1 in direct scanout; VRR
	59	+	// turns variable refresh on while a buffer is scanned out.
	60	+	Tearing, VRR bool
58	61		}
59	62		Log struct {
60	63		Level string


@@ -55,6 +55,9 @@ type Config struct {
55	Binds map[string]string	55		Binds map[string]string
56	Render struct {	56		Render struct {
57	DirectScanout bool	57		DirectScanout bool
		58	+	// Tearing honours wp_tearing_control_v1 in direct scanout; VRR
		59	+	// turns variable refresh on while a buffer is scanned out.
		60	+	Tearing, VRR bool
58	}	61		}
59	Log struct {	62		Log struct {
60	Level string	63		Level string

M internal/ports/messages.go +3 -0


@@ -543,6 +543,9 @@ type SurfaceContent struct {
543	543		// Geometry is in logical pixels from the surface origin; empty means
544	544		// the whole surface.
545	545		Geometry Rect
	546	+	// Async asks for tearing presentation (wp_tearing_control_v1); outputs
	547	+	// honour it only in direct scanout.
	548	+	Async bool
546	549		}
547	550
548	551		// Subsurface is a child surface at X, Y logical pixels from the root


@@ -543,6 +543,9 @@ type SurfaceContent struct {
543	// Geometry is in logical pixels from the surface origin; empty means	543		// Geometry is in logical pixels from the surface origin; empty means
544	// the whole surface.	544		// the whole surface.
545	Geometry Rect	545		Geometry Rect
		546	+	// Async asks for tearing presentation (wp_tearing_control_v1); outputs
		547	+	// honour it only in direct scanout.
		548	+	Async bool
546	}	549		}
547		550
548	// Subsurface is a child surface at X, Y logical pixels from the root	551		// Subsurface is a child surface at X, Y logical pixels from the root