[PATCH] drm/panel: atna33xc20: Fix unbalanced regulator in the case HPD doesn't assert

[PATCH] drm/panel: atna33xc20: Fix unbalanced regulator in the case HPD doesn't assert

[Douglas Anderson via B4 Relay]

From: Douglas Anderson <dianders@chromium.org>

When the atna33xc20 driver was first written the resume code never
returned an error. If there was a problem waiting for HPD it just
printed a warning and moved on. This changed in response to review
feedback [1] on a future patch but I accidentally didn't account for
rolling back the regulator enable in the error cases. Do so now.

[1] https://lore.kernel.org/all/5f3cf3a6-1cc2-63e4-f76b-4ee686764705@linaro.org/

Fixes: 3b5765df375c ("drm/panel: atna33xc20: Take advantage of wait_hpd_asserted() in struct drm_dp_aux")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
 drivers/gpu/drm/panel/panel-samsung-atna33xc20.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
index 76c2a8f6718c..9c336c71562b 100644
--- a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
+++ b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
@@ -109,19 +109,17 @@ static int atana33xc20_resume(struct device *dev)
 		if (hpd_asserted < 0)
 			ret = hpd_asserted;
 
-		if (ret)
+		if (ret) {
 			dev_warn(dev, "Error waiting for HPD GPIO: %d\n", ret);
-
-		return ret;
-	}
-
-	if (p->aux->wait_hpd_asserted) {
+			goto error;
+		}
+	} else if (p->aux->wait_hpd_asserted) {
 		ret = p->aux->wait_hpd_asserted(p->aux, HPD_MAX_US);
 
-		if (ret)
+		if (ret) {
 			dev_warn(dev, "Controller error waiting for HPD: %d\n", ret);
-
-		return ret;
+			goto error;
+		}
 	}
 
 	/*
@@ -133,6 +131,12 @@ static int atana33xc20_resume(struct device *dev)
 	 * right times.
 	 */
 	return 0;
+
+error:
+	drm_dp_dpcd_set_powered(p->aux, false);
+	regulator_disable(p->supply);
+
+	return ret;
 }
 
 static int atana33xc20_disable(struct drm_panel *panel)

---
base-commit: b33651a5c98dbd5a919219d8c129d0674ef74299
change-id: 20240311-homestarpanel-regulator-f4b890ff4b7c

Best regards,
-- 
Douglas Anderson <dianders@chromium.org>

Re: [PATCH] drm/panel: atna33xc20: Fix unbalanced regulator in the case HPD doesn't assert

[Jessica Zhang]

On 3/13/2024 2:12 PM, Douglas Anderson via B4 Relay wrote:
> From: Douglas Anderson <dianders@chromium.org>
> 
> When the atna33xc20 driver was first written the resume code never
> returned an error. If there was a problem waiting for HPD it just
> printed a warning and moved on. This changed in response to review
> feedback [1] on a future patch but I accidentally didn't account for
> rolling back the regulator enable in the error cases. Do so now.
> 
> [1] https://lore.kernel.org/all/5f3cf3a6-1cc2-63e4-f76b-4ee686764705@linaro.org/
> 
> Fixes: 3b5765df375c ("drm/panel: atna33xc20: Take advantage of wait_hpd_asserted() in struct drm_dp_aux")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
>   drivers/gpu/drm/panel/panel-samsung-atna33xc20.c | 22 +++++++++++++---------
>   1 file changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
> index 76c2a8f6718c..9c336c71562b 100644
> --- a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
> +++ b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
> @@ -109,19 +109,17 @@ static int atana33xc20_resume(struct device *dev)
>   		if (hpd_asserted < 0)
>   			ret = hpd_asserted;
>   
> -		if (ret)
> +		if (ret) {
>   			dev_warn(dev, "Error waiting for HPD GPIO: %d\n", ret);
> -
> -		return ret;
> -	}
> -
> -	if (p->aux->wait_hpd_asserted) {
> +			goto error;
> +		}
> +	} else if (p->aux->wait_hpd_asserted) {

Hi Doug,

Acked-by: Jessica Zhang <quic_jesszhan@quicinc.com>

Thanks,

Jessica Zhang

>   		ret = p->aux->wait_hpd_asserted(p->aux, HPD_MAX_US);
>   
> -		if (ret)
> +		if (ret) {
>   			dev_warn(dev, "Controller error waiting for HPD: %d\n", ret);
> -
> -		return ret;
> +			goto error;
> +		}
>   	}
>   
>   	/*
> @@ -133,6 +131,12 @@ static int atana33xc20_resume(struct device *dev)
>   	 * right times.
>   	 */
>   	return 0;
> +
> +error:
> +	drm_dp_dpcd_set_powered(p->aux, false);
> +	regulator_disable(p->supply);
> +
> +	return ret;
>   }
>   
>   static int atana33xc20_disable(struct drm_panel *panel)
> 
> ---
> base-commit: b33651a5c98dbd5a919219d8c129d0674ef74299
> change-id: 20240311-homestarpanel-regulator-f4b890ff4b7c
> 
> Best regards,
> -- 
> Douglas Anderson <dianders@chromium.org>
> 

Re: [PATCH] drm/panel: atna33xc20: Fix unbalanced regulator in the case HPD doesn't assert

[Doug Anderson]

Hi,

On Thu, Mar 14, 2024 at 3:32 PM Jessica Zhang <quic_jesszhan@quicinc.com> wrote:
>
> On 3/13/2024 2:12 PM, Douglas Anderson via B4 Relay wrote:
> > From: Douglas Anderson <dianders@chromium.org>
> >
> > When the atna33xc20 driver was first written the resume code never
> > returned an error. If there was a problem waiting for HPD it just
> > printed a warning and moved on. This changed in response to review
> > feedback [1] on a future patch but I accidentally didn't account for
> > rolling back the regulator enable in the error cases. Do so now.
> >
> > [1] https://lore.kernel.org/all/5f3cf3a6-1cc2-63e4-f76b-4ee686764705@linaro.org/
> >
> > Fixes: 3b5765df375c ("drm/panel: atna33xc20: Take advantage of wait_hpd_asserted() in struct drm_dp_aux")
> > Signed-off-by: Douglas Anderson <dianders@chromium.org>
> > ---
> >   drivers/gpu/drm/panel/panel-samsung-atna33xc20.c | 22 +++++++++++++---------
> >   1 file changed, 13 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
> > index 76c2a8f6718c..9c336c71562b 100644
> > --- a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
> > +++ b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
> > @@ -109,19 +109,17 @@ static int atana33xc20_resume(struct device *dev)
> >               if (hpd_asserted < 0)
> >                       ret = hpd_asserted;
> >
> > -             if (ret)
> > +             if (ret) {
> >                       dev_warn(dev, "Error waiting for HPD GPIO: %d\n", ret);
> > -
> > -             return ret;
> > -     }
> > -
> > -     if (p->aux->wait_hpd_asserted) {
> > +                     goto error;
> > +             }
> > +     } else if (p->aux->wait_hpd_asserted) {
>
> Hi Doug,
>
> Acked-by: Jessica Zhang <quic_jesszhan@quicinc.com>

Pushed with Jessica's Ack to drm-misc-next.

5e842d55bad7 drm/panel: atna33xc20: Fix unbalanced regulator in the
case HPD doesn't assert

I chose drm-misc-next instead of drm-misc-fixes because this isn't
super urgent and the patch would have to be modified on drm-misc-fixes
because we don't have commit 8df1ddb5bf11 ("drm/dp: Don't attempt AUX
transfers when eDP panels are not powered") there.

Re: [PATCH] drm/panel: atna33xc20: Fix unbalanced regulator in the case HPD doesn't assert

[Neil Armstrong]

On 20/03/2024 16:33, Doug Anderson wrote:
> Hi,
> 
> On Thu, Mar 14, 2024 at 3:32 PM Jessica Zhang <quic_jesszhan@quicinc.com> wrote:
>>
>> On 3/13/2024 2:12 PM, Douglas Anderson via B4 Relay wrote:
>>> From: Douglas Anderson <dianders@chromium.org>
>>>
>>> When the atna33xc20 driver was first written the resume code never
>>> returned an error. If there was a problem waiting for HPD it just
>>> printed a warning and moved on. This changed in response to review
>>> feedback [1] on a future patch but I accidentally didn't account for
>>> rolling back the regulator enable in the error cases. Do so now.
>>>
>>> [1] https://lore.kernel.org/all/5f3cf3a6-1cc2-63e4-f76b-4ee686764705@linaro.org/
>>>
>>> Fixes: 3b5765df375c ("drm/panel: atna33xc20: Take advantage of wait_hpd_asserted() in struct drm_dp_aux")
>>> Signed-off-by: Douglas Anderson <dianders@chromium.org>
>>> ---
>>>    drivers/gpu/drm/panel/panel-samsung-atna33xc20.c | 22 +++++++++++++---------
>>>    1 file changed, 13 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
>>> index 76c2a8f6718c..9c336c71562b 100644
>>> --- a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
>>> +++ b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
>>> @@ -109,19 +109,17 @@ static int atana33xc20_resume(struct device *dev)
>>>                if (hpd_asserted < 0)
>>>                        ret = hpd_asserted;
>>>
>>> -             if (ret)
>>> +             if (ret) {
>>>                        dev_warn(dev, "Error waiting for HPD GPIO: %d\n", ret);
>>> -
>>> -             return ret;
>>> -     }
>>> -
>>> -     if (p->aux->wait_hpd_asserted) {
>>> +                     goto error;
>>> +             }
>>> +     } else if (p->aux->wait_hpd_asserted) {
>>
>> Hi Doug,
>>
>> Acked-by: Jessica Zhang <quic_jesszhan@quicinc.com>
> 
> Pushed with Jessica's Ack to drm-misc-next.
> 
> 5e842d55bad7 drm/panel: atna33xc20: Fix unbalanced regulator in the
> case HPD doesn't assert
> 
> I chose drm-misc-next instead of drm-misc-fixes because this isn't
> super urgent and the patch would have to be modified on drm-misc-fixes
> because we don't have commit 8df1ddb5bf11 ("drm/dp: Don't attempt AUX
> transfers when eDP panels are not powered") there.

Thx I wasn't really sure where to push this so I waited v6.9-rc1 to decide!