[PATCH] drm/rockchip: Suspend DP late

[PATCH] drm/rockchip: Suspend DP late

[Douglas Anderson]

In commit fe64ba5c6323 ("drm/rockchip: Resume DP early") we moved
resume to be early but left suspend at its normal time.  This seems
like it could be OK, but casues problems if a suspend gets interrupted
partway through.  The OS only balances matching suspend/resume levels.
...so if suspend was called then resume will be called.  If suspend
late was called then resume early will be called.  ...but if suspend
was called resume early might not get called.  This leads to an
unbalance in the clock enables / disables.

Lets take the simple fix and just move suspend to be late to match.
This makes the PM core take proper care in keeping things balanced.

Fixes: fe64ba5c6323 ("drm/rockchip: Resume DP early")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

 drivers/gpu/drm/rockchip/analogix_dp-rockchip.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
index 7d7cb57410fc..f38f5e113c6b 100644
--- a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
@@ -436,7 +436,7 @@ static int rockchip_dp_resume(struct device *dev)
 
 static const struct dev_pm_ops rockchip_dp_pm_ops = {
 #ifdef CONFIG_PM_SLEEP
-	.suspend = rockchip_dp_suspend,
+	.suspend_late = rockchip_dp_suspend,
 	.resume_early = rockchip_dp_resume,
 #endif
 };
-- 
2.22.0.770.g0f2c4a37fd-goog

Re: [PATCH] drm/rockchip: Suspend DP late

[Sean Paul]

On Fri, Aug 02, 2019 at 11:46:16AM -0700, Douglas Anderson wrote:
> In commit fe64ba5c6323 ("drm/rockchip: Resume DP early") we moved
> resume to be early but left suspend at its normal time.  This seems
> like it could be OK, but casues problems if a suspend gets interrupted
> partway through.  The OS only balances matching suspend/resume levels.
> ...so if suspend was called then resume will be called.  If suspend
> late was called then resume early will be called.  ...but if suspend
> was called resume early might not get called.  This leads to an
> unbalance in the clock enables / disables.
> 
> Lets take the simple fix and just move suspend to be late to match.
> This makes the PM core take proper care in keeping things balanced.
> 
> Fixes: fe64ba5c6323 ("drm/rockchip: Resume DP early")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Reviewed-by: Sean Paul <sean@poorly.run>

This should go in -misc-fixes and due to some... administrative reasons... I
will leave it on the list until Maarten has a chance to ff to -rc4 on Monday.
I'll apply it then so as to not require a backmerge.

Sean

> ---
> 
>  drivers/gpu/drm/rockchip/analogix_dp-rockchip.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
> index 7d7cb57410fc..f38f5e113c6b 100644
> --- a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
> @@ -436,7 +436,7 @@ static int rockchip_dp_resume(struct device *dev)
>  
>  static const struct dev_pm_ops rockchip_dp_pm_ops = {
>  #ifdef CONFIG_PM_SLEEP
> -	.suspend = rockchip_dp_suspend,
> +	.suspend_late = rockchip_dp_suspend,
>  	.resume_early = rockchip_dp_resume,
>  #endif
>  };
> -- 
> 2.22.0.770.g0f2c4a37fd-goog
> 

-- 
Sean Paul, Software Engineer, Google / Chromium OS

Re: [PATCH] drm/rockchip: Suspend DP late

[Sean Paul]

On Fri, Aug 02, 2019 at 03:26:29PM -0400, Sean Paul wrote:
> On Fri, Aug 02, 2019 at 11:46:16AM -0700, Douglas Anderson wrote:
> > In commit fe64ba5c6323 ("drm/rockchip: Resume DP early") we moved
> > resume to be early but left suspend at its normal time.  This seems
> > like it could be OK, but casues problems if a suspend gets interrupted
> > partway through.  The OS only balances matching suspend/resume levels.
> > ...so if suspend was called then resume will be called.  If suspend
> > late was called then resume early will be called.  ...but if suspend
> > was called resume early might not get called.  This leads to an
> > unbalance in the clock enables / disables.
> > 
> > Lets take the simple fix and just move suspend to be late to match.
> > This makes the PM core take proper care in keeping things balanced.
> > 
> > Fixes: fe64ba5c6323 ("drm/rockchip: Resume DP early")
> > Signed-off-by: Douglas Anderson <dianders@chromium.org>
> 
> Reviewed-by: Sean Paul <sean@poorly.run>
> 
> This should go in -misc-fixes and due to some... administrative reasons... I
> will leave it on the list until Maarten has a chance to ff to -rc4 on Monday.
> I'll apply it then so as to not require a backmerge.

We're no longer able to ff drm-misc-fixes since a commit came in on Saturday, so
I've piled this on as well.

Thanks,

Sean

> 
> Sean
> 
> > ---
> > 
> >  drivers/gpu/drm/rockchip/analogix_dp-rockchip.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
> > index 7d7cb57410fc..f38f5e113c6b 100644
> > --- a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
> > +++ b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
> > @@ -436,7 +436,7 @@ static int rockchip_dp_resume(struct device *dev)
> >  
> >  static const struct dev_pm_ops rockchip_dp_pm_ops = {
> >  #ifdef CONFIG_PM_SLEEP
> > -	.suspend = rockchip_dp_suspend,
> > +	.suspend_late = rockchip_dp_suspend,
> >  	.resume_early = rockchip_dp_resume,
> >  #endif
> >  };
> > -- 
> > 2.22.0.770.g0f2c4a37fd-goog
> > 
> 
> -- 
> Sean Paul, Software Engineer, Google / Chromium OS

-- 
Sean Paul, Software Engineer, Google / Chromium OS