* [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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