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authorTakashi Iwai <tiwai@suse.de>2016-10-20 17:05:30 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-11-10 16:38:54 +0100
commit6222f1e0b9ef0d0c89183cadcc1e780661ce08d3 (patch)
treedeafc385019446ff694b0cc1dcc1531678921395
parent7290da41b8da4a8a6819966cb9922170f5ae70c6 (diff)
drm/fb-helper: Don't call dirty callback for untouched clips
commit 87d3b6588f9bf205902868d3e5baf68e37ad4ae1 upstream. 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: eaa434defaca ('drm/fb-helper: Add fb_deferred_io support') 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 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/gpu/drm/drm_fb_helper.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 0a06f9120b5a..91b46ffa92c2 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -632,7 +632,9 @@ static void drm_fb_helper_dirty_work(struct work_struct *work)
clip->x2 = clip->y2 = 0;
spin_unlock_irqrestore(&helper->dirty_lock, flags);
- helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
+ /* call dirty callback only when it has been really touched */
+ if (clip_copy.x1 < clip_copy.x2 && clip_copy.y1 < clip_copy.y2)
+ helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
}
/**