Searched hist:dc5bdb68 (Results 1 – 3 of 3) sorted by relevance
/openbmc/linux/include/uapi/linux/ |
H A D | fb.h | dc5bdb68 Wed Jun 24 04:29:10 CDT 2020 Daniel Vetter <daniel.vetter@ffwll.ch> drm/fb-helper: Fix vt restore
In the past we had a pile of hacks to orchestrate access between fbdev emulation and native kms clients. We've tried to streamline this, by always preferring the kms side above fbdev calls when a drm master exists, because drm master controls access to the display resources.
Unfortunately this breaks existing userspace, specifically Xorg. When exiting Xorg first restores the console to text mode using the KDSET ioctl on the vt. This does nothing, because a drm master is still around. Then it drops the drm master status, which again does nothing, because logind is keeping additional drm fd open to be able to orchestrate vt switches. In the past this is the point where fbdev was restored, as part of the ->lastclose hook on the drm side.
Now to fix this regression we don't want to go back to letting fbdev restore things whenever it feels like, or to the pile of hacks we've had before. Instead try and go with a minimal exception to make the KDSET case work again, and nothing else.
This means that if userspace does a KDSET call when switching between graphical compositors, there will be some flickering with fbcon showing up for a bit. But a) that's not a regression and b) userspace can fix it by improving the vt switching dance - logind should have all the information it needs.
While pondering all this I'm also wondering wheter we should have a SWITCH_MASTER ioctl to allow race-free master status handover. But that's for another day.
v2: Somehow forgot to cc all the fbdev people.
v3: Fix typo Alex spotted.
Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=208179 Cc: shlomo@fastmail.com Reported-and-Tested-by: shlomo@fastmail.com Cc: Michel Dänzer <michel@daenzer.net> Fixes: 64914da24ea9 ("drm/fbdev-helper: don't force restores") Cc: Noralf Trønnes <noralf@tronnes.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: dri-devel@lists.freedesktop.org Cc: <stable@vger.kernel.org> # v5.7+ Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Qiujun Huang <hqjagain@gmail.com> Cc: Peter Rosin <peda@axentia.se> Cc: linux-fbdev@vger.kernel.org Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200624092910.3280448-1-daniel.vetter@ffwll.ch dc5bdb68 Wed Jun 24 04:29:10 CDT 2020 Daniel Vetter <daniel.vetter@ffwll.ch> drm/fb-helper: Fix vt restore In the past we had a pile of hacks to orchestrate access between fbdev emulation and native kms clients. We've tried to streamline this, by always preferring the kms side above fbdev calls when a drm master exists, because drm master controls access to the display resources. Unfortunately this breaks existing userspace, specifically Xorg. When exiting Xorg first restores the console to text mode using the KDSET ioctl on the vt. This does nothing, because a drm master is still around. Then it drops the drm master status, which again does nothing, because logind is keeping additional drm fd open to be able to orchestrate vt switches. In the past this is the point where fbdev was restored, as part of the ->lastclose hook on the drm side. Now to fix this regression we don't want to go back to letting fbdev restore things whenever it feels like, or to the pile of hacks we've had before. Instead try and go with a minimal exception to make the KDSET case work again, and nothing else. This means that if userspace does a KDSET call when switching between graphical compositors, there will be some flickering with fbcon showing up for a bit. But a) that's not a regression and b) userspace can fix it by improving the vt switching dance - logind should have all the information it needs. While pondering all this I'm also wondering wheter we should have a SWITCH_MASTER ioctl to allow race-free master status handover. But that's for another day. v2: Somehow forgot to cc all the fbdev people. v3: Fix typo Alex spotted. Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=208179 Cc: shlomo@fastmail.com Reported-and-Tested-by: shlomo@fastmail.com Cc: Michel Dänzer <michel@daenzer.net> Fixes: 64914da24ea9 ("drm/fbdev-helper: don't force restores") Cc: Noralf Trønnes <noralf@tronnes.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: dri-devel@lists.freedesktop.org Cc: <stable@vger.kernel.org> # v5.7+ Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Qiujun Huang <hqjagain@gmail.com> Cc: Peter Rosin <peda@axentia.se> Cc: linux-fbdev@vger.kernel.org Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200624092910.3280448-1-daniel.vetter@ffwll.ch
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/openbmc/linux/drivers/video/fbdev/core/ |
H A D | fbcon.c | dc5bdb68 Wed Jun 24 04:29:10 CDT 2020 Daniel Vetter <daniel.vetter@ffwll.ch> drm/fb-helper: Fix vt restore
In the past we had a pile of hacks to orchestrate access between fbdev emulation and native kms clients. We've tried to streamline this, by always preferring the kms side above fbdev calls when a drm master exists, because drm master controls access to the display resources.
Unfortunately this breaks existing userspace, specifically Xorg. When exiting Xorg first restores the console to text mode using the KDSET ioctl on the vt. This does nothing, because a drm master is still around. Then it drops the drm master status, which again does nothing, because logind is keeping additional drm fd open to be able to orchestrate vt switches. In the past this is the point where fbdev was restored, as part of the ->lastclose hook on the drm side.
Now to fix this regression we don't want to go back to letting fbdev restore things whenever it feels like, or to the pile of hacks we've had before. Instead try and go with a minimal exception to make the KDSET case work again, and nothing else.
This means that if userspace does a KDSET call when switching between graphical compositors, there will be some flickering with fbcon showing up for a bit. But a) that's not a regression and b) userspace can fix it by improving the vt switching dance - logind should have all the information it needs.
While pondering all this I'm also wondering wheter we should have a SWITCH_MASTER ioctl to allow race-free master status handover. But that's for another day.
v2: Somehow forgot to cc all the fbdev people.
v3: Fix typo Alex spotted.
Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=208179 Cc: shlomo@fastmail.com Reported-and-Tested-by: shlomo@fastmail.com Cc: Michel Dänzer <michel@daenzer.net> Fixes: 64914da24ea9 ("drm/fbdev-helper: don't force restores") Cc: Noralf Trønnes <noralf@tronnes.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: dri-devel@lists.freedesktop.org Cc: <stable@vger.kernel.org> # v5.7+ Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Qiujun Huang <hqjagain@gmail.com> Cc: Peter Rosin <peda@axentia.se> Cc: linux-fbdev@vger.kernel.org Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200624092910.3280448-1-daniel.vetter@ffwll.ch
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/openbmc/linux/drivers/gpu/drm/ |
H A D | drm_fb_helper.c | dc5bdb68 Wed Jun 24 04:29:10 CDT 2020 Daniel Vetter <daniel.vetter@ffwll.ch> drm/fb-helper: Fix vt restore
In the past we had a pile of hacks to orchestrate access between fbdev emulation and native kms clients. We've tried to streamline this, by always preferring the kms side above fbdev calls when a drm master exists, because drm master controls access to the display resources.
Unfortunately this breaks existing userspace, specifically Xorg. When exiting Xorg first restores the console to text mode using the KDSET ioctl on the vt. This does nothing, because a drm master is still around. Then it drops the drm master status, which again does nothing, because logind is keeping additional drm fd open to be able to orchestrate vt switches. In the past this is the point where fbdev was restored, as part of the ->lastclose hook on the drm side.
Now to fix this regression we don't want to go back to letting fbdev restore things whenever it feels like, or to the pile of hacks we've had before. Instead try and go with a minimal exception to make the KDSET case work again, and nothing else.
This means that if userspace does a KDSET call when switching between graphical compositors, there will be some flickering with fbcon showing up for a bit. But a) that's not a regression and b) userspace can fix it by improving the vt switching dance - logind should have all the information it needs.
While pondering all this I'm also wondering wheter we should have a SWITCH_MASTER ioctl to allow race-free master status handover. But that's for another day.
v2: Somehow forgot to cc all the fbdev people.
v3: Fix typo Alex spotted.
Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=208179 Cc: shlomo@fastmail.com Reported-and-Tested-by: shlomo@fastmail.com Cc: Michel Dänzer <michel@daenzer.net> Fixes: 64914da24ea9 ("drm/fbdev-helper: don't force restores") Cc: Noralf Trønnes <noralf@tronnes.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: dri-devel@lists.freedesktop.org Cc: <stable@vger.kernel.org> # v5.7+ Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Qiujun Huang <hqjagain@gmail.com> Cc: Peter Rosin <peda@axentia.se> Cc: linux-fbdev@vger.kernel.org Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200624092910.3280448-1-daniel.vetter@ffwll.ch
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