| Message ID | 20190919132759.18358-1-mihail.atanassov@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/komeda: Fix FLIP_COMPLETE timestamp on CRTC enable | expand |
On Thursday, 19 September 2019 14:30:02 BST Mihail Atanassov wrote: > 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 > Please ignore, this doesn't work (page flips after 5 seconds don't get an updated timestamp because of the delayed vsync disable). I'll push a v2 soon where vsync on/off tracks crtc enable/disable.
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
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(+)