[PATCH 108/133] drm: Don't pass negative delta to ktime_sub_ns()
3.8.13.7 -stable review patch. If anyone has any objections, please let me
know.
--
From: =?UTF-8?q?Michel=20D=C3=A4nzer?=
commit e91abf80a0998f326107874c88d549f94839f13c upstream.
It takes an unsigned value. This happens not to blow up on 64-bit
architectures, but it does on 32-bit, causing
drm_calc_vbltimestamp_from_scanoutpos() to calculate totally bogus
timestamps for vblank events. Which in turn causes e.g. gnome-shell to
hang after a DPMS off cycle with current xf86-video-ati Git.
[airlied: regression introduced in drm: use monotonic time in
drm_calc_vbltimestamp_from_scanoutpos]
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=59339
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=59836
Tested-by: shui yangwei
Signed-off-by: Michel Dänzer
Reviewed-by: Imre Deak
Signed-off-by: Dave Airlie
Signed-off-by: Kamal Mostafa
---
drivers/gpu/drm/drm_irq.c | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 570dac6..0f3cdda 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -704,7 +704,10 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct
drm_device *dev, int crtc,
/* Subtract time delta from raw timestamp to get final
* vblank_time timestamp for end of vblank.
*/
- etime = ktime_sub_ns(etime, delta_ns);
+ if (delta_ns < 0)
+ etime = ktime_add_ns(etime, -delta_ns);
+ else
+ etime = ktime_sub_ns(etime, delta_ns);
*vblank_time = ktime_to_timeval(etime);
DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d
rep]\n",
--
1.8.1.2
--
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[PATCH 108/133] drm: Don't pass negative delta to ktime_sub_ns()
3.8.13.7 -stable review patch. If anyone has any objections, please let me know. -- From: =?UTF-8?q?Michel=20D=C3=A4nzer?= michel.daen...@amd.com commit e91abf80a0998f326107874c88d549f94839f13c upstream. It takes an unsigned value. This happens not to blow up on 64-bit architectures, but it does on 32-bit, causing drm_calc_vbltimestamp_from_scanoutpos() to calculate totally bogus timestamps for vblank events. Which in turn causes e.g. gnome-shell to hang after a DPMS off cycle with current xf86-video-ati Git. [airlied: regression introduced in drm: use monotonic time in drm_calc_vbltimestamp_from_scanoutpos] Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=59339 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=59836 Tested-by: shui yangwei yangweix.s...@intel.com Signed-off-by: Michel Dänzer michel.daen...@amd.com Reviewed-by: Imre Deak imre.d...@intel.com Signed-off-by: Dave Airlie airl...@redhat.com Signed-off-by: Kamal Mostafa ka...@canonical.com --- drivers/gpu/drm/drm_irq.c | 5 - 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 570dac6..0f3cdda 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -704,7 +704,10 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc, /* Subtract time delta from raw timestamp to get final * vblank_time timestamp for end of vblank. */ - etime = ktime_sub_ns(etime, delta_ns); + if (delta_ns 0) + etime = ktime_add_ns(etime, -delta_ns); + else + etime = ktime_sub_ns(etime, delta_ns); *vblank_time = ktime_to_timeval(etime); DRM_DEBUG(crtc %d : v %d p(%d,%d)@ %ld.%ld - %ld.%ld [e %d us, %d rep]\n, -- 1.8.1.2 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
