Messages in this thread Patch in this message | | | From | Mihail Atanassov <> | Subject | [PATCH] drm/komeda: Fix FLIP_COMPLETE timestamp on CRTC enable | Date | Thu, 19 Sep 2019 13:30:02 +0000 |
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When initially turning a crtc on, drm_reset_vblank_timestamp will set the vblank timestamp to 0 for any driver that doesn't provide a ->get_vblank_timestamp() hook.
Unfortunately, the FLIP_COMPLETE event depends on that timestamp, and the only way to regenerate a valid one is to have vblank interrupts enabled and have a valid in-ISR call to drm_crtc_handle_vblank.
Wrap the call to komeda_crtc_do_flush in ->atomic_enable() with a drm_crtc_vblank_{get,put} pair so we can have a vblank ISR prior to the FLIP_COMPLETE ISR (or more likely, they'll get handled in the same ISR, which is equally valid).
Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Liviu Dudau <Liviu.Dudau@arm.com> Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com> --- drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c index f4400788ab94..87420a767bc4 100644 --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c @@ -258,7 +258,9 @@ komeda_crtc_atomic_enable(struct drm_crtc *crtc, { komeda_crtc_prepare(to_kcrtc(crtc)); drm_crtc_vblank_on(crtc); + WARN_ON(drm_crtc_vblank_get(crtc)); komeda_crtc_do_flush(crtc, old); + drm_crtc_vblank_put(crtc); } static void -- 2.23.0
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