2020-01-20 13:48:28

by Yannick FERTRE

[permalink] [raw]
Subject: [PATCH] drm/stm: ltdc: enable/disable depends on encoder

From: Yannick Fertré <[email protected]>

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.

Signed-off-by: Yannick Fertré <[email protected]>
---
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 = {
--
2.7.4


2020-01-23 09:48:58

by Philippe Cornu

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

Dear Yannick,
Thank you for your patch,

Acked-by: Philippe Cornu <[email protected]>

Philippe :-)

On 1/20/20 2:46 PM, Yannick Fertre wrote:
> From: Yannick Fertré <[email protected]>
>
> 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.
>
> Signed-off-by: Yannick Fertré <[email protected]>
> ---
> 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 = {
>

2020-02-04 11:00:01

by Benjamin Gaignard

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

Le jeu. 23 janv. 2020 à 10:47, Philippe CORNU <[email protected]> a écrit :
>
> Dear Yannick,
> Thank you for your patch,
>
> Acked-by: Philippe Cornu <[email protected]>
>
> Philippe :-)
>
> On 1/20/20 2:46 PM, Yannick Fertre wrote:
> > From: Yannick Fertré <[email protected]>
> >
> > 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 Fertré <[email protected]>
> > ---
> > 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 = {
> >
> _______________________________________________
> linux-arm-kernel mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel