linux/drivers/gpu
Takashi Iwai 87d3b6588f drm/fb-helper: Don't call dirty callback for untouched clips
Since 4.7 kernel, we've seen the error messages like

 kernel: [TTM] Buffer eviction failed
 kernel: qxl 0000:00:02.0: object_init failed for (4026540032, 0x00000001)
 kernel: [drm:qxl_alloc_bo_reserved [qxl]] *ERROR* failed to allocate VRAM BO

on QXL when switching and accessing on VT.  The culprit was the
generic deferred_io code (qxl driver switched to it since 4.7).
There is a race between the dirty clip update and the call of
callback.

In drm_fb_helper_dirty(), the dirty clip is updated in the spinlock,
while it kicks off the update worker outside the spinlock.  Meanwhile
the update worker clears the dirty clip in the spinlock, too.  Thus,
when drm_fb_helper_dirty() is called concurrently, schedule_work() is
called after the clip is cleared in the first worker call.

This patch addresses it by validating the clip before calling the
dirty fb callback.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98322
Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1003298
Fixes: eaa434defa ('drm/fb-helper: Add fb_deferred_io support')
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161020150530.5787-1-tiwai@suse.de
2016-10-26 10:31:53 +02:00
..
drm drm/fb-helper: Don't call dirty callback for untouched clips 2016-10-26 10:31:53 +02:00
host1x drm/tegra: dsi: Enhance runtime power management 2016-08-24 15:58:57 +02:00
ipu-v3 gpu: ipu-v3: Add queued image conversion support 2016-09-19 08:30:27 +02:00
vga vgaarbiter: rst-ifiy and polish kerneldoc 2016-08-16 18:49:56 +02:00
Makefile