2020-01-21 10:16:47

by Yannick FERTRE

Subject: [PATCH] drm/stm: ltdc: check crtc state before enabling LIE

Following investigations of a hardware bug, the LIE interrupt
can occur while the display controller is not activated.
LIE interrupt (vblank) don't have to be set if the CRTC is not
enabled.

Signed-off-by: Yannick Fertre <[email protected]>
---
drivers/gpu/drm/stm/ltdc.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index c2815e8..ea654c7 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -648,9 +648,14 @@ static const struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = {
static int ltdc_crtc_enable_vblank(struct drm_crtc *crtc)
{
struct ltdc_device *ldev = crtc_to_ltdc(crtc);
+ struct drm_crtc_state *state = crtc->state;

DRM_DEBUG_DRIVER("\n");
- reg_set(ldev->regs, LTDC_IER, IER_LIE);
+
+ if (state->enable)
+ reg_set(ldev->regs, LTDC_IER, IER_LIE);
+ else
+ return -EPERM;

return 0;
}
--
2.7.4

2020-01-23 09:51:59

by Philippe Cornu

Subject: Re: [PATCH] drm/stm: ltdc: check crtc state before enabling LIE

Dear Yannick,
Thank you for your patch,

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

Philippe :-)

On 1/21/20 11:14 AM, Yannick Fertre wrote:
> Following investigations of a hardware bug, the LIE interrupt
> can occur while the display controller is not activated.
> LIE interrupt (vblank) don't have to be set if the CRTC is not
> enabled.
>
> Signed-off-by: Yannick Fertre <[email protected]>
> ---
> drivers/gpu/drm/stm/ltdc.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
> index c2815e8..ea654c7 100644
> --- a/drivers/gpu/drm/stm/ltdc.c
> +++ b/drivers/gpu/drm/stm/ltdc.c
> @@ -648,9 +648,14 @@ static const struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = {
> static int ltdc_crtc_enable_vblank(struct drm_crtc *crtc)
> {
> struct ltdc_device *ldev = crtc_to_ltdc(crtc);
> + struct drm_crtc_state *state = crtc->state;
>
> DRM_DEBUG_DRIVER("\n");
> - reg_set(ldev->regs, LTDC_IER, IER_LIE);
> +
> + if (state->enable)
> + reg_set(ldev->regs, LTDC_IER, IER_LIE);
> + else
> + return -EPERM;
>
> return 0;
> }
>

2020-02-04 11:00:19

by Benjamin Gaignard

Subject: Re: [PATCH] drm/stm: ltdc: check crtc state before enabling LIE

Le jeu. 23 janv. 2020 à 10:50, Philippe CORNU <[email protected]> a écrit :
>
> Dear Yannick,
> Thank you for your patch,
>
> Acked-by: Philippe Cornu <[email protected]>
>
> Philippe :-)
>
> On 1/21/20 11:14 AM, Yannick Fertre wrote:
> > Following investigations of a hardware bug, the LIE interrupt
> > can occur while the display controller is not activated.
> > LIE interrupt (vblank) don't have to be set if the CRTC is not
> > enabled.
> >

Applied on drm-misc-next.

Thanks
Benjamin

> > Signed-off-by: Yannick Fertre <[email protected]>
> > ---
> > drivers/gpu/drm/stm/ltdc.c | 7 ++++++-
> > 1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
> > index c2815e8..ea654c7 100644
> > --- a/drivers/gpu/drm/stm/ltdc.c
> > +++ b/drivers/gpu/drm/stm/ltdc.c
> > @@ -648,9 +648,14 @@ static const struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = {
> > static int ltdc_crtc_enable_vblank(struct drm_crtc *crtc)
> > {
> > struct ltdc_device *ldev = crtc_to_ltdc(crtc);
> > + struct drm_crtc_state *state = crtc->state;
> >
> > DRM_DEBUG_DRIVER("\n");
> > - reg_set(ldev->regs, LTDC_IER, IER_LIE);
> > +
> > + if (state->enable)
> > + reg_set(ldev->regs, LTDC_IER, IER_LIE);
> > + else
> > + return -EPERM;
> >
> > return 0;
> > }
> >
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