Commit bcbec31c authored Nov 13, 2017 by Ville Syrjälä

drm/vblank: Fix vblank timestamp debugs



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: 67680d3c ("drm: vblank: use ktime_t instead of timeval")
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Keith Packard <keithp@keithp.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171113150210.11311-1-ville.syrjala@linux.intel.com


Acked-by: Arnd Bergmann <arnd@arndb.de>

parent 44a2d564

drivers/gpu/drm/drm_vblank.c

+7 −5

Original line number	Diff line number	Diff line
		@@ -664,14 +664,16 @@ bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
		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,