Re: [PATCH] drm/stm: ltdc: enable/disable depends on encoder

From: Benjamin Gaignard
Date: Tue Feb 04 2020 - 05:57:00 EST


Le jeu. 23 janv. 2020 Ã 10:47, Philippe CORNU <philippe.cornu@xxxxxx> a Ãcrit :
>
> Dear Yannick,
> Thank you for your patch,
>
> Acked-by: Philippe Cornu <philippe.cornu@xxxxxx>
>
> Philippe :-)
>
> On 1/20/20 2:46 PM, Yannick Fertre wrote:
> > From: Yannick Fertrà <yannick.fertre@xxxxxx>
> >
> > When connected to a dsi host, the ltdc display controller
> > must send frames only after the end of the dsi panel
> > initialization to avoid errors when the dsi host sends
> > commands to the dsi panel (dsi px fifo full).
> > To avoid this issue, the display controller must be
> > enabled/disabled when the encoder is enabled/disabled.
> >

Applied on drm-misc-next.

Thanks
Benjamin

> > Signed-off-by: Yannick Fertrà <yannick.fertre@xxxxxx>
> > ---
> > drivers/gpu/drm/stm/ltdc.c | 14 ++++++++------
> > 1 file changed, 8 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
> > index 719dfc5..9ef125d 100644
> > --- a/drivers/gpu/drm/stm/ltdc.c
> > +++ b/drivers/gpu/drm/stm/ltdc.c
> > @@ -437,9 +437,6 @@ static void ltdc_crtc_atomic_enable(struct drm_crtc *crtc,
> > /* Commit shadow registers = update planes at next vblank */
> > reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
> >
> > - /* Enable LTDC */
> > - reg_set(ldev->regs, LTDC_GCR, GCR_LTDCEN);
> > -
> > drm_crtc_vblank_on(crtc);
> > }
> >
> > @@ -453,9 +450,6 @@ static void ltdc_crtc_atomic_disable(struct drm_crtc *crtc,
> >
> > drm_crtc_vblank_off(crtc);
> >
> > - /* disable LTDC */
> > - reg_clear(ldev->regs, LTDC_GCR, GCR_LTDCEN);
> > -
> > /* disable IRQ */
> > reg_clear(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
> >
> > @@ -1058,9 +1052,13 @@ static const struct drm_encoder_funcs ltdc_encoder_funcs = {
> > static void ltdc_encoder_disable(struct drm_encoder *encoder)
> > {
> > struct drm_device *ddev = encoder->dev;
> > + struct ltdc_device *ldev = ddev->dev_private;
> >
> > DRM_DEBUG_DRIVER("\n");
> >
> > + /* Disable LTDC */
> > + reg_clear(ldev->regs, LTDC_GCR, GCR_LTDCEN);
> > +
> > /* Set to sleep state the pinctrl whatever type of encoder */
> > pinctrl_pm_select_sleep_state(ddev->dev);
> > }
> > @@ -1068,6 +1066,7 @@ static void ltdc_encoder_disable(struct drm_encoder *encoder)
> > static void ltdc_encoder_enable(struct drm_encoder *encoder)
> > {
> > struct drm_device *ddev = encoder->dev;
> > + struct ltdc_device *ldev = ddev->dev_private;
> >
> > DRM_DEBUG_DRIVER("\n");
> >
> > @@ -1078,6 +1077,9 @@ static void ltdc_encoder_enable(struct drm_encoder *encoder)
> > */
> > if (encoder->encoder_type == DRM_MODE_ENCODER_DPI)
> > pinctrl_pm_select_default_state(ddev->dev);
> > +
> > + /* Enable LTDC */
> > + reg_set(ldev->regs, LTDC_GCR, GCR_LTDCEN);
> > }
> >
> > static const struct drm_encoder_helper_funcs ltdc_encoder_helper_funcs = {
> >
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