* [PATCH] drm: Fix broken VT switch with video=1366x768 option @ 2017-01-09 14:56 Takashi Iwai 2017-01-10 11:28 ` Ville Syrjälä 0 siblings, 1 reply; 7+ messages in thread From: Takashi Iwai @ 2017-01-09 14:56 UTC (permalink / raw) To: dri-devel; +Cc: linux-kernel, Ville Syrjälä I noticed that the VT switch doesn't work any longer with a Dell laptop with 1366x768 eDP when the machine is connected with a DP monitor. It behaves as if VT were switched, but the graphics remain frozen. Actually the keyboard works, so I could switch back to VT7 again. I tried to track down the problem, and encountered a long story until we reach to this error: - The machine is booted with video=1366x768 option (the distro installer seems to add it as default). - Recently, drm_helper_probe_single_connector_modes() deals with cmdline modes, and it tries to create a new mode when no matching mode is found. - The drm_mode_create_from_cmdline_mode() creates a mode based on either CVT of GFT according to the given cmdline mode; in our case, it's 1366x768. - Since both CVT and GFT can't express the width 1366 due to alignment, the resultant mode becomes 1368x768, slightly larger than the given size. - Later on, the atomic commit is performed, and in drm_atomic_check_only(), the size of each plane is checked. - The size check of 1366x768 fails due to the above, and eventually the whole VT switch fails. Back in the history, we've had a manual fix-up of 1368x768 in various places via c09dedb7a50e ("drm/edid: Add a workaround for 1366x768 HD panel"), but they have been all in drm_edid.c at probing the modes from EDID. For addressing the problem above, we need a similar hack to the mode newly created from cmdline, manually adjusting the width when the expected size is 1366 while we get 1368 instead. Fixes: eaf99c749d43 ("drm: Perform cmdline mode parsing during...") Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> --- drivers/gpu/drm/drm_modes.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c index ac6a35212501..e6b19bc9021a 100644 --- a/drivers/gpu/drm/drm_modes.c +++ b/drivers/gpu/drm/drm_modes.c @@ -1460,6 +1460,13 @@ drm_mode_create_from_cmdline_mode(struct drm_device *dev, return NULL; mode->type |= DRM_MODE_TYPE_USERDEF; + /* fix up 1368x768: GFT/CVT can't express 1366 width due to alignment */ + if (cmd->xres == 1366 && mode->hdisplay == 1368) { + mode->hdisplay = 1366; + mode->hsync_start--; + mode->hsync_end--; + drm_mode_set_name(mode); + } drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V); return mode; } -- 2.11.0 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] drm: Fix broken VT switch with video=1366x768 option 2017-01-09 14:56 [PATCH] drm: Fix broken VT switch with video=1366x768 option Takashi Iwai @ 2017-01-10 11:28 ` Ville Syrjälä 2017-01-10 11:36 ` Takashi Iwai 0 siblings, 1 reply; 7+ messages in thread From: Ville Syrjälä @ 2017-01-10 11:28 UTC (permalink / raw) To: Takashi Iwai; +Cc: dri-devel, linux-kernel On Mon, Jan 09, 2017 at 03:56:14PM +0100, Takashi Iwai wrote: > I noticed that the VT switch doesn't work any longer with a Dell > laptop with 1366x768 eDP when the machine is connected with a DP > monitor. It behaves as if VT were switched, but the graphics remain > frozen. Actually the keyboard works, so I could switch back to VT7 > again. > > I tried to track down the problem, and encountered a long story until > we reach to this error: > > - The machine is booted with video=1366x768 option (the distro > installer seems to add it as default). > - Recently, drm_helper_probe_single_connector_modes() deals with > cmdline modes, and it tries to create a new mode when no > matching mode is found. > - The drm_mode_create_from_cmdline_mode() creates a mode based on > either CVT of GFT according to the given cmdline mode; in our case, > it's 1366x768. > - Since both CVT and GFT can't express the width 1366 due to > alignment, the resultant mode becomes 1368x768, slightly larger than > the given size. > - Later on, the atomic commit is performed, and in > drm_atomic_check_only(), the size of each plane is checked. > - The size check of 1366x768 fails due to the above, and eventually > the whole VT switch fails. > > Back in the history, we've had a manual fix-up of 1368x768 in various > places via c09dedb7a50e ("drm/edid: Add a workaround for 1366x768 HD > panel"), but they have been all in drm_edid.c at probing the modes > from EDID. For addressing the problem above, we need a similar hack > to the mode newly created from cmdline, manually adjusting the width > when the expected size is 1366 while we get 1368 instead. > > Fixes: eaf99c749d43 ("drm: Perform cmdline mode parsing during...") > Cc: <stable@vger.kernel.org> > Signed-off-by: Takashi Iwai <tiwai@suse.de> > --- > drivers/gpu/drm/drm_modes.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c > index ac6a35212501..e6b19bc9021a 100644 > --- a/drivers/gpu/drm/drm_modes.c > +++ b/drivers/gpu/drm/drm_modes.c > @@ -1460,6 +1460,13 @@ drm_mode_create_from_cmdline_mode(struct drm_device *dev, > return NULL; > > mode->type |= DRM_MODE_TYPE_USERDEF; > + /* fix up 1368x768: GFT/CVT can't express 1366 width due to alignment */ > + if (cmd->xres == 1366 && mode->hdisplay == 1368) { > + mode->hdisplay = 1366; > + mode->hsync_start--; > + mode->hsync_end--; > + drm_mode_set_name(mode); > + } Maybe give fixup_mode_1366x768() a drm_ prefix and make in non-static to avoid duplicating the code? And I guess move it to drm_modes.c? Otherwise lgtm: Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V); > return mode; > } > -- > 2.11.0 -- Ville Syrjälä Intel OTC ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] drm: Fix broken VT switch with video=1366x768 option 2017-01-10 11:28 ` Ville Syrjälä @ 2017-01-10 11:36 ` Takashi Iwai 2017-01-10 12:41 ` Daniel Vetter 0 siblings, 1 reply; 7+ messages in thread From: Takashi Iwai @ 2017-01-10 11:36 UTC (permalink / raw) To: Ville Syrjälä; +Cc: dri-devel, linux-kernel On Tue, 10 Jan 2017 12:28:36 +0100, Ville Syrjälä wrote: > > On Mon, Jan 09, 2017 at 03:56:14PM +0100, Takashi Iwai wrote: > > I noticed that the VT switch doesn't work any longer with a Dell > > laptop with 1366x768 eDP when the machine is connected with a DP > > monitor. It behaves as if VT were switched, but the graphics remain > > frozen. Actually the keyboard works, so I could switch back to VT7 > > again. > > > > I tried to track down the problem, and encountered a long story until > > we reach to this error: > > > > - The machine is booted with video=1366x768 option (the distro > > installer seems to add it as default). > > - Recently, drm_helper_probe_single_connector_modes() deals with > > cmdline modes, and it tries to create a new mode when no > > matching mode is found. > > - The drm_mode_create_from_cmdline_mode() creates a mode based on > > either CVT of GFT according to the given cmdline mode; in our case, > > it's 1366x768. > > - Since both CVT and GFT can't express the width 1366 due to > > alignment, the resultant mode becomes 1368x768, slightly larger than > > the given size. > > - Later on, the atomic commit is performed, and in > > drm_atomic_check_only(), the size of each plane is checked. > > - The size check of 1366x768 fails due to the above, and eventually > > the whole VT switch fails. > > > > Back in the history, we've had a manual fix-up of 1368x768 in various > > places via c09dedb7a50e ("drm/edid: Add a workaround for 1366x768 HD > > panel"), but they have been all in drm_edid.c at probing the modes > > from EDID. For addressing the problem above, we need a similar hack > > to the mode newly created from cmdline, manually adjusting the width > > when the expected size is 1366 while we get 1368 instead. > > > > Fixes: eaf99c749d43 ("drm: Perform cmdline mode parsing during...") > > Cc: <stable@vger.kernel.org> > > Signed-off-by: Takashi Iwai <tiwai@suse.de> > > --- > > drivers/gpu/drm/drm_modes.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c > > index ac6a35212501..e6b19bc9021a 100644 > > --- a/drivers/gpu/drm/drm_modes.c > > +++ b/drivers/gpu/drm/drm_modes.c > > @@ -1460,6 +1460,13 @@ drm_mode_create_from_cmdline_mode(struct drm_device *dev, > > return NULL; > > > > mode->type |= DRM_MODE_TYPE_USERDEF; > > + /* fix up 1368x768: GFT/CVT can't express 1366 width due to alignment */ > > + if (cmd->xres == 1366 && mode->hdisplay == 1368) { > > + mode->hdisplay = 1366; > > + mode->hsync_start--; > > + mode->hsync_end--; > > + drm_mode_set_name(mode); > > + } > > Maybe give fixup_mode_1366x768() a drm_ prefix and make in non-static to > avoid duplicating the code? And I guess move it to drm_modes.c? Yes, that'll be a good cleanup. I was afraid of symbol export, but both are in the same module, so far. I can post a follow-up once when this one gets accepted. > > Otherwise lgtm: > Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Thanks! Takashi > > drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V); > > return mode; > > } > > -- > > 2.11.0 > > -- > Ville Syrjälä > Intel OTC > ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] drm: Fix broken VT switch with video=1366x768 option 2017-01-10 11:36 ` Takashi Iwai @ 2017-01-10 12:41 ` Daniel Vetter 2017-01-10 12:45 ` Takashi Iwai 2017-01-11 17:05 ` Ville Syrjälä 0 siblings, 2 replies; 7+ messages in thread From: Daniel Vetter @ 2017-01-10 12:41 UTC (permalink / raw) To: Takashi Iwai; +Cc: Ville Syrjälä, linux-kernel, dri-devel On Tue, Jan 10, 2017 at 12:36:50PM +0100, Takashi Iwai wrote: > On Tue, 10 Jan 2017 12:28:36 +0100, > Ville Syrjälä wrote: > > > > On Mon, Jan 09, 2017 at 03:56:14PM +0100, Takashi Iwai wrote: > > > I noticed that the VT switch doesn't work any longer with a Dell > > > laptop with 1366x768 eDP when the machine is connected with a DP > > > monitor. It behaves as if VT were switched, but the graphics remain > > > frozen. Actually the keyboard works, so I could switch back to VT7 > > > again. > > > > > > I tried to track down the problem, and encountered a long story until > > > we reach to this error: > > > > > > - The machine is booted with video=1366x768 option (the distro > > > installer seems to add it as default). > > > - Recently, drm_helper_probe_single_connector_modes() deals with > > > cmdline modes, and it tries to create a new mode when no > > > matching mode is found. > > > - The drm_mode_create_from_cmdline_mode() creates a mode based on > > > either CVT of GFT according to the given cmdline mode; in our case, > > > it's 1366x768. > > > - Since both CVT and GFT can't express the width 1366 due to > > > alignment, the resultant mode becomes 1368x768, slightly larger than > > > the given size. > > > - Later on, the atomic commit is performed, and in > > > drm_atomic_check_only(), the size of each plane is checked. > > > - The size check of 1366x768 fails due to the above, and eventually > > > the whole VT switch fails. > > > > > > Back in the history, we've had a manual fix-up of 1368x768 in various > > > places via c09dedb7a50e ("drm/edid: Add a workaround for 1366x768 HD > > > panel"), but they have been all in drm_edid.c at probing the modes > > > from EDID. For addressing the problem above, we need a similar hack > > > to the mode newly created from cmdline, manually adjusting the width > > > when the expected size is 1366 while we get 1368 instead. > > > > > > Fixes: eaf99c749d43 ("drm: Perform cmdline mode parsing during...") > > > Cc: <stable@vger.kernel.org> > > > Signed-off-by: Takashi Iwai <tiwai@suse.de> > > > --- > > > drivers/gpu/drm/drm_modes.c | 7 +++++++ > > > 1 file changed, 7 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c > > > index ac6a35212501..e6b19bc9021a 100644 > > > --- a/drivers/gpu/drm/drm_modes.c > > > +++ b/drivers/gpu/drm/drm_modes.c > > > @@ -1460,6 +1460,13 @@ drm_mode_create_from_cmdline_mode(struct drm_device *dev, > > > return NULL; > > > > > > mode->type |= DRM_MODE_TYPE_USERDEF; > > > + /* fix up 1368x768: GFT/CVT can't express 1366 width due to alignment */ > > > + if (cmd->xres == 1366 && mode->hdisplay == 1368) { > > > + mode->hdisplay = 1366; > > > + mode->hsync_start--; > > > + mode->hsync_end--; > > > + drm_mode_set_name(mode); > > > + } > > > > Maybe give fixup_mode_1366x768() a drm_ prefix and make in non-static to > > avoid duplicating the code? And I guess move it to drm_modes.c? > > Yes, that'll be a good cleanup. I was afraid of symbol export, but > both are in the same module, so far. I can post a follow-up once when > this one gets accepted. For the follow up, pls put the decl into drm_crtc_internal.h, so that drivers aren't tempted to use it. That header is for module-internal shared code only. > > Otherwise lgtm: > > Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > > Thanks! Ville, can you pls also apply this one to drm-misc-fixes? -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] drm: Fix broken VT switch with video=1366x768 option 2017-01-10 12:41 ` Daniel Vetter @ 2017-01-10 12:45 ` Takashi Iwai 2017-01-11 17:05 ` Ville Syrjälä 1 sibling, 0 replies; 7+ messages in thread From: Takashi Iwai @ 2017-01-10 12:45 UTC (permalink / raw) To: Daniel Vetter; +Cc: Ville Syrjälä, linux-kernel, dri-devel On Tue, 10 Jan 2017 13:41:42 +0100, Daniel Vetter wrote: > > On Tue, Jan 10, 2017 at 12:36:50PM +0100, Takashi Iwai wrote: > > On Tue, 10 Jan 2017 12:28:36 +0100, > > Ville Syrjälä wrote: > > > > > > On Mon, Jan 09, 2017 at 03:56:14PM +0100, Takashi Iwai wrote: > > > > I noticed that the VT switch doesn't work any longer with a Dell > > > > laptop with 1366x768 eDP when the machine is connected with a DP > > > > monitor. It behaves as if VT were switched, but the graphics remain > > > > frozen. Actually the keyboard works, so I could switch back to VT7 > > > > again. > > > > > > > > I tried to track down the problem, and encountered a long story until > > > > we reach to this error: > > > > > > > > - The machine is booted with video=1366x768 option (the distro > > > > installer seems to add it as default). > > > > - Recently, drm_helper_probe_single_connector_modes() deals with > > > > cmdline modes, and it tries to create a new mode when no > > > > matching mode is found. > > > > - The drm_mode_create_from_cmdline_mode() creates a mode based on > > > > either CVT of GFT according to the given cmdline mode; in our case, > > > > it's 1366x768. > > > > - Since both CVT and GFT can't express the width 1366 due to > > > > alignment, the resultant mode becomes 1368x768, slightly larger than > > > > the given size. > > > > - Later on, the atomic commit is performed, and in > > > > drm_atomic_check_only(), the size of each plane is checked. > > > > - The size check of 1366x768 fails due to the above, and eventually > > > > the whole VT switch fails. > > > > > > > > Back in the history, we've had a manual fix-up of 1368x768 in various > > > > places via c09dedb7a50e ("drm/edid: Add a workaround for 1366x768 HD > > > > panel"), but they have been all in drm_edid.c at probing the modes > > > > from EDID. For addressing the problem above, we need a similar hack > > > > to the mode newly created from cmdline, manually adjusting the width > > > > when the expected size is 1366 while we get 1368 instead. > > > > > > > > Fixes: eaf99c749d43 ("drm: Perform cmdline mode parsing during...") > > > > Cc: <stable@vger.kernel.org> > > > > Signed-off-by: Takashi Iwai <tiwai@suse.de> > > > > --- > > > > drivers/gpu/drm/drm_modes.c | 7 +++++++ > > > > 1 file changed, 7 insertions(+) > > > > > > > > diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c > > > > index ac6a35212501..e6b19bc9021a 100644 > > > > --- a/drivers/gpu/drm/drm_modes.c > > > > +++ b/drivers/gpu/drm/drm_modes.c > > > > @@ -1460,6 +1460,13 @@ drm_mode_create_from_cmdline_mode(struct drm_device *dev, > > > > return NULL; > > > > > > > > mode->type |= DRM_MODE_TYPE_USERDEF; > > > > + /* fix up 1368x768: GFT/CVT can't express 1366 width due to alignment */ > > > > + if (cmd->xres == 1366 && mode->hdisplay == 1368) { > > > > + mode->hdisplay = 1366; > > > > + mode->hsync_start--; > > > > + mode->hsync_end--; > > > > + drm_mode_set_name(mode); > > > > + } > > > > > > Maybe give fixup_mode_1366x768() a drm_ prefix and make in non-static to > > > avoid duplicating the code? And I guess move it to drm_modes.c? > > > > Yes, that'll be a good cleanup. I was afraid of symbol export, but > > both are in the same module, so far. I can post a follow-up once when > > this one gets accepted. > > For the follow up, pls put the decl into drm_crtc_internal.h, so that > drivers aren't tempted to use it. That header is for module-internal > shared code only. Alright, thanks for information. Takashi ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] drm: Fix broken VT switch with video=1366x768 option 2017-01-10 12:41 ` Daniel Vetter 2017-01-10 12:45 ` Takashi Iwai @ 2017-01-11 17:05 ` Ville Syrjälä 2017-01-11 18:46 ` Takashi Iwai 1 sibling, 1 reply; 7+ messages in thread From: Ville Syrjälä @ 2017-01-11 17:05 UTC (permalink / raw) To: Takashi Iwai, linux-kernel, dri-devel On Tue, Jan 10, 2017 at 01:41:42PM +0100, Daniel Vetter wrote: > On Tue, Jan 10, 2017 at 12:36:50PM +0100, Takashi Iwai wrote: > > On Tue, 10 Jan 2017 12:28:36 +0100, > > Ville Syrjälä wrote: > > > > > > On Mon, Jan 09, 2017 at 03:56:14PM +0100, Takashi Iwai wrote: > > > > I noticed that the VT switch doesn't work any longer with a Dell > > > > laptop with 1366x768 eDP when the machine is connected with a DP > > > > monitor. It behaves as if VT were switched, but the graphics remain > > > > frozen. Actually the keyboard works, so I could switch back to VT7 > > > > again. > > > > > > > > I tried to track down the problem, and encountered a long story until > > > > we reach to this error: > > > > > > > > - The machine is booted with video=1366x768 option (the distro > > > > installer seems to add it as default). > > > > - Recently, drm_helper_probe_single_connector_modes() deals with > > > > cmdline modes, and it tries to create a new mode when no > > > > matching mode is found. > > > > - The drm_mode_create_from_cmdline_mode() creates a mode based on > > > > either CVT of GFT according to the given cmdline mode; in our case, > > > > it's 1366x768. > > > > - Since both CVT and GFT can't express the width 1366 due to > > > > alignment, the resultant mode becomes 1368x768, slightly larger than > > > > the given size. > > > > - Later on, the atomic commit is performed, and in > > > > drm_atomic_check_only(), the size of each plane is checked. > > > > - The size check of 1366x768 fails due to the above, and eventually > > > > the whole VT switch fails. > > > > > > > > Back in the history, we've had a manual fix-up of 1368x768 in various > > > > places via c09dedb7a50e ("drm/edid: Add a workaround for 1366x768 HD > > > > panel"), but they have been all in drm_edid.c at probing the modes > > > > from EDID. For addressing the problem above, we need a similar hack > > > > to the mode newly created from cmdline, manually adjusting the width > > > > when the expected size is 1366 while we get 1368 instead. > > > > > > > > Fixes: eaf99c749d43 ("drm: Perform cmdline mode parsing during...") > > > > Cc: <stable@vger.kernel.org> > > > > Signed-off-by: Takashi Iwai <tiwai@suse.de> > > > > --- > > > > drivers/gpu/drm/drm_modes.c | 7 +++++++ > > > > 1 file changed, 7 insertions(+) > > > > > > > > diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c > > > > index ac6a35212501..e6b19bc9021a 100644 > > > > --- a/drivers/gpu/drm/drm_modes.c > > > > +++ b/drivers/gpu/drm/drm_modes.c > > > > @@ -1460,6 +1460,13 @@ drm_mode_create_from_cmdline_mode(struct drm_device *dev, > > > > return NULL; > > > > > > > > mode->type |= DRM_MODE_TYPE_USERDEF; > > > > + /* fix up 1368x768: GFT/CVT can't express 1366 width due to alignment */ > > > > + if (cmd->xres == 1366 && mode->hdisplay == 1368) { > > > > + mode->hdisplay = 1366; > > > > + mode->hsync_start--; > > > > + mode->hsync_end--; > > > > + drm_mode_set_name(mode); > > > > + } > > > > > > Maybe give fixup_mode_1366x768() a drm_ prefix and make in non-static to > > > avoid duplicating the code? And I guess move it to drm_modes.c? > > > > Yes, that'll be a good cleanup. I was afraid of symbol export, but > > both are in the same module, so far. I can post a follow-up once when > > this one gets accepted. > > For the follow up, pls put the decl into drm_crtc_internal.h, so that > drivers aren't tempted to use it. That header is for module-internal > shared code only. > > > > Otherwise lgtm: > > > Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > > > > Thanks! > > Ville, can you pls also apply this one to drm-misc-fixes? Pushed. Thanks for the patch. -- Ville Syrjälä Intel OTC ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] drm: Fix broken VT switch with video=1366x768 option 2017-01-11 17:05 ` Ville Syrjälä @ 2017-01-11 18:46 ` Takashi Iwai 0 siblings, 0 replies; 7+ messages in thread From: Takashi Iwai @ 2017-01-11 18:46 UTC (permalink / raw) To: Ville Syrjälä; +Cc: linux-kernel, dri-devel On Wed, 11 Jan 2017 18:05:12 +0100, Ville Syrjälä wrote: > > On Tue, Jan 10, 2017 at 01:41:42PM +0100, Daniel Vetter wrote: > > On Tue, Jan 10, 2017 at 12:36:50PM +0100, Takashi Iwai wrote: > > > On Tue, 10 Jan 2017 12:28:36 +0100, > > > Ville Syrjälä wrote: > > > > > > > > On Mon, Jan 09, 2017 at 03:56:14PM +0100, Takashi Iwai wrote: > > > > > I noticed that the VT switch doesn't work any longer with a Dell > > > > > laptop with 1366x768 eDP when the machine is connected with a DP > > > > > monitor. It behaves as if VT were switched, but the graphics remain > > > > > frozen. Actually the keyboard works, so I could switch back to VT7 > > > > > again. > > > > > > > > > > I tried to track down the problem, and encountered a long story until > > > > > we reach to this error: > > > > > > > > > > - The machine is booted with video=1366x768 option (the distro > > > > > installer seems to add it as default). > > > > > - Recently, drm_helper_probe_single_connector_modes() deals with > > > > > cmdline modes, and it tries to create a new mode when no > > > > > matching mode is found. > > > > > - The drm_mode_create_from_cmdline_mode() creates a mode based on > > > > > either CVT of GFT according to the given cmdline mode; in our case, > > > > > it's 1366x768. > > > > > - Since both CVT and GFT can't express the width 1366 due to > > > > > alignment, the resultant mode becomes 1368x768, slightly larger than > > > > > the given size. > > > > > - Later on, the atomic commit is performed, and in > > > > > drm_atomic_check_only(), the size of each plane is checked. > > > > > - The size check of 1366x768 fails due to the above, and eventually > > > > > the whole VT switch fails. > > > > > > > > > > Back in the history, we've had a manual fix-up of 1368x768 in various > > > > > places via c09dedb7a50e ("drm/edid: Add a workaround for 1366x768 HD > > > > > panel"), but they have been all in drm_edid.c at probing the modes > > > > > from EDID. For addressing the problem above, we need a similar hack > > > > > to the mode newly created from cmdline, manually adjusting the width > > > > > when the expected size is 1366 while we get 1368 instead. > > > > > > > > > > Fixes: eaf99c749d43 ("drm: Perform cmdline mode parsing during...") > > > > > Cc: <stable@vger.kernel.org> > > > > > Signed-off-by: Takashi Iwai <tiwai@suse.de> > > > > > --- > > > > > drivers/gpu/drm/drm_modes.c | 7 +++++++ > > > > > 1 file changed, 7 insertions(+) > > > > > > > > > > diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c > > > > > index ac6a35212501..e6b19bc9021a 100644 > > > > > --- a/drivers/gpu/drm/drm_modes.c > > > > > +++ b/drivers/gpu/drm/drm_modes.c > > > > > @@ -1460,6 +1460,13 @@ drm_mode_create_from_cmdline_mode(struct drm_device *dev, > > > > > return NULL; > > > > > > > > > > mode->type |= DRM_MODE_TYPE_USERDEF; > > > > > + /* fix up 1368x768: GFT/CVT can't express 1366 width due to alignment */ > > > > > + if (cmd->xres == 1366 && mode->hdisplay == 1368) { > > > > > + mode->hdisplay = 1366; > > > > > + mode->hsync_start--; > > > > > + mode->hsync_end--; > > > > > + drm_mode_set_name(mode); > > > > > + } > > > > > > > > Maybe give fixup_mode_1366x768() a drm_ prefix and make in non-static to > > > > avoid duplicating the code? And I guess move it to drm_modes.c? > > > > > > Yes, that'll be a good cleanup. I was afraid of symbol export, but > > > both are in the same module, so far. I can post a follow-up once when > > > this one gets accepted. > > > > For the follow up, pls put the decl into drm_crtc_internal.h, so that > > drivers aren't tempted to use it. That header is for module-internal > > shared code only. > > > > > > Otherwise lgtm: > > > > Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > > > > > > Thanks! > > > > Ville, can you pls also apply this one to drm-misc-fixes? > > Pushed. Thanks for the patch. Thanks! Takashi ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2017-01-11 18:46 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2017-01-09 14:56 [PATCH] drm: Fix broken VT switch with video=1366x768 option Takashi Iwai 2017-01-10 11:28 ` Ville Syrjälä 2017-01-10 11:36 ` Takashi Iwai 2017-01-10 12:41 ` Daniel Vetter 2017-01-10 12:45 ` Takashi Iwai 2017-01-11 17:05 ` Ville Syrjälä 2017-01-11 18:46 ` Takashi Iwai
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