3.10-stable review patch. If anyone has any objections, please let me know.
------------------ From: Michel Dänzer <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: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- drivers/gpu/drm/drm_irq.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -708,7 +708,10 @@ int drm_calc_vbltimestamp_from_scanoutpo /* 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", -- 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/
