This is a note to let you know that I've just added the patch titled
drm/vblank: Fix vblank timestamp debugs
to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-vblank-fix-vblank-timestamp-debugs.patch
and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Fri Mar 16 15:11:07 CET 2018
From: "Ville Syrjälä" <ville.syrjala@xxxxxxxxxxxxxxx>
Date: Mon, 13 Nov 2017 17:02:10 +0200
Subject: drm/vblank: Fix vblank timestamp debugs
From: "Ville Syrjälä" <ville.syrjala@xxxxxxxxxxxxxxx>
[ Upstream commit bcbec31ce500fe036f75a19bca5c73bfa6dd420b ]
We're currently calling ktime_to_timespec64() on stack garbage
hence the debug output for vblank timestamps also contains garbage.
Let's assing something to the ktime_t first before we go converting
it to a timespec.
While at it micro-optimize the ktime_to_timespec64() calls away
when vblank debugging isn't enabled.
Fixes: 67680d3c0464 ("drm: vblank: use ktime_t instead of timeval")
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Keith Packard <keithp@xxxxxxxxxx>
Cc: Sean Paul <seanpaul@xxxxxxxxxxxx>
Cc: Dave Airlie <airlied@xxxxxxxxxx>
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20171113150210.11311-1-ville.syrjala@xxxxxxxxxxxxxxx
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_vblank.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -663,14 +663,16 @@ bool drm_calc_vbltimestamp_from_scanoutp
delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos),
mode->crtc_clock);
- /* save this only for debugging purposes */
- ts_etime = ktime_to_timespec64(etime);
- ts_vblank_time = ktime_to_timespec64(*vblank_time);
/* Subtract time delta from raw timestamp to get final
* vblank_time timestamp for end of vblank.
*/
- etime = ktime_sub_ns(etime, delta_ns);
- *vblank_time = etime;
+ *vblank_time = ktime_sub_ns(etime, delta_ns);
+
+ if ((drm_debug & DRM_UT_VBL) == 0)
+ return true;
+
+ ts_etime = ktime_to_timespec64(etime);
+ ts_vblank_time = ktime_to_timespec64(*vblank_time);
DRM_DEBUG_VBL("crtc %u : v p(%d,%d)@ %lld.%06ld -> %lld.%06ld [e %d us, %d rep]\n",
pipe, hpos, vpos,
Patches currently in stable-queue which might be from ville.syrjala@xxxxxxxxxxxxxxx are
queue-4.15/drm-vblank-fix-vblank-timestamp-debugs.patch
queue-4.15/video-hdmi-allow-empty-hdmi-infoframes.patch
queue-4.15/drm-edid-set-eld-connector-type-in-drm_edid_to_eld.patch