| Message ID | 3d00592745e9559b754e84ffc74b4a727b82e8ab.1594230107.git-series.maxime@cerno.tech (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/vc4: Support BCM2711 Display Pipeline | expand |
Hi Maxime On Wed, 8 Jul 2020 at 18:42, Maxime Ripard <maxime@cerno.tech> wrote: > > The VIDEN bit in the pixelvalve currently being used to enable or disable > the pixelvalve seems to not be enough in some situations, which whill end > up with the pixelvalve stalling. > > In such a case, even re-enabling VIDEN doesn't bring it back and we need to > clear the FIFO. This can only be done if the pixelvalve is disabled though. > > In order to overcome this, we can configure the pixelvalve during > mode_set_no_fb, but only enable it in atomic_enable and flush the FIFO > there, and in atomic_disable disable the pixelvalve again. Very minor nitpick: the configure is in vc4_crtc_config_pv, but that is called from mode_set_no_fb. The comment is correct from a DRM overview perspective, but not from the actual code. Describing the DRM call is probably the better approach, but it looks odd when compared to the code. > Signed-off-by: Maxime Ripard <maxime@cerno.tech> Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com> > --- > drivers/gpu/drm/vc4/vc4_crtc.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c > index cdeaa0cd981f..fe2e5675aed4 100644 > --- a/drivers/gpu/drm/vc4/vc4_crtc.c > +++ b/drivers/gpu/drm/vc4/vc4_crtc.c > @@ -332,9 +332,7 @@ static void vc4_crtc_config_pv(struct drm_crtc *crtc) > PV_CONTROL_TRIGGER_UNDERFLOW | > PV_CONTROL_WAIT_HSTART | > VC4_SET_FIELD(vc4_encoder->clock_select, > - PV_CONTROL_CLK_SELECT) | > - PV_CONTROL_FIFO_CLR | > - PV_CONTROL_EN); > + PV_CONTROL_CLK_SELECT)); > } > > static void vc4_crtc_mode_set_nofb(struct drm_crtc *crtc) > @@ -386,6 +384,8 @@ static void vc4_crtc_atomic_disable(struct drm_crtc *crtc, > ret = wait_for(!(CRTC_READ(PV_V_CONTROL) & PV_VCONTROL_VIDEN), 1); > WARN_ONCE(ret, "Timeout waiting for !PV_VCONTROL_VIDEN\n"); > > + CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) & ~PV_CONTROL_EN); > + > vc4_hvs_atomic_disable(crtc, old_state); > > /* > @@ -410,6 +410,10 @@ static void vc4_crtc_atomic_enable(struct drm_crtc *crtc, > > require_hvs_enabled(dev); > > + /* Reset the PV fifo. */ > + CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) | > + PV_CONTROL_FIFO_CLR | PV_CONTROL_EN); > + > /* Enable vblank irq handling before crtc is started otherwise > * drm_crtc_get_vblank() fails in vc4_crtc_update_dlist(). > */ > -- > git-series 0.9.1
diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c index cdeaa0cd981f..fe2e5675aed4 100644 --- a/drivers/gpu/drm/vc4/vc4_crtc.c +++ b/drivers/gpu/drm/vc4/vc4_crtc.c @@ -332,9 +332,7 @@ static void vc4_crtc_config_pv(struct drm_crtc *crtc) PV_CONTROL_TRIGGER_UNDERFLOW | PV_CONTROL_WAIT_HSTART | VC4_SET_FIELD(vc4_encoder->clock_select, - PV_CONTROL_CLK_SELECT) | - PV_CONTROL_FIFO_CLR | - PV_CONTROL_EN); + PV_CONTROL_CLK_SELECT)); } static void vc4_crtc_mode_set_nofb(struct drm_crtc *crtc) @@ -386,6 +384,8 @@ static void vc4_crtc_atomic_disable(struct drm_crtc *crtc, ret = wait_for(!(CRTC_READ(PV_V_CONTROL) & PV_VCONTROL_VIDEN), 1); WARN_ONCE(ret, "Timeout waiting for !PV_VCONTROL_VIDEN\n"); + CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) & ~PV_CONTROL_EN); + vc4_hvs_atomic_disable(crtc, old_state); /* @@ -410,6 +410,10 @@ static void vc4_crtc_atomic_enable(struct drm_crtc *crtc, require_hvs_enabled(dev); + /* Reset the PV fifo. */ + CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) | + PV_CONTROL_FIFO_CLR | PV_CONTROL_EN); + /* Enable vblank irq handling before crtc is started otherwise * drm_crtc_get_vblank() fails in vc4_crtc_update_dlist(). */
The VIDEN bit in the pixelvalve currently being used to enable or disable the pixelvalve seems to not be enough in some situations, which whill end up with the pixelvalve stalling. In such a case, even re-enabling VIDEN doesn't bring it back and we need to clear the FIFO. This can only be done if the pixelvalve is disabled though. In order to overcome this, we can configure the pixelvalve during mode_set_no_fb, but only enable it in atomic_enable and flush the FIFO there, and in atomic_disable disable the pixelvalve again. Signed-off-by: Maxime Ripard <maxime@cerno.tech> --- drivers/gpu/drm/vc4/vc4_crtc.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)