[PATCH] drm/rockchip: cdn-dp: Fix error handling

[PATCH] drm/rockchip: cdn-dp: Fix error handling

[Christophe JAILLET]

It is likely that both 'clk_disable_unprepare()' should be called if
'pm_runtime_get_sync()' fails.

Add a new label for that, because 'err_set_rate' is not meaningful in this
case.


Fixes: 1a0f7ed3abe2 ("drm/rockchip: cdn-dp: add cdn DP support for rk3399")

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Not sure but a 'pm_runtime_get_sync()' is maybe also required in the
'err_set_rate' path.
---
 drivers/gpu/drm/rockchip/cdn-dp-core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c b/drivers/gpu/drm/rockchip/cdn-dp-core.c
index 9ab67a670885..0fe1ec8b8fb1 100644
--- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
+++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
@@ -111,7 +111,7 @@ static int cdn_dp_clk_enable(struct cdn_dp_device *dp)
 	ret = pm_runtime_get_sync(dp->dev);
 	if (ret < 0) {
 		DRM_DEV_ERROR(dp->dev, "cannot get pm runtime %d\n", ret);
-		goto err_pclk;
+		goto err_sync;
 	}
 
 	reset_control_assert(dp->core_rst);
@@ -133,6 +133,7 @@ static int cdn_dp_clk_enable(struct cdn_dp_device *dp)
 	return 0;
 
 err_set_rate:
+err_sync:
 	clk_disable_unprepare(dp->core_clk);
 err_core_clk:
 	clk_disable_unprepare(dp->pclk);
-- 
2.9.3

Re: [PATCH] drm/rockchip: cdn-dp: Fix error handling

[Mark yao]

On 2017年02月20日 00:59, Christophe JAILLET wrote:
> It is likely that both 'clk_disable_unprepare()' should be called if
> 'pm_runtime_get_sync()' fails.
>
> Add a new label for that, because 'err_set_rate' is not meaningful in this
> case.
>
>
> Fixes: 1a0f7ed3abe2 ("drm/rockchip: cdn-dp: add cdn DP support for rk3399")
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> Not sure but a 'pm_runtime_get_sync()' is maybe also required in the
> 'err_set_rate' path.
> ---
>   drivers/gpu/drm/rockchip/cdn-dp-core.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c b/drivers/gpu/drm/rockchip/cdn-dp-core.c
> index 9ab67a670885..0fe1ec8b8fb1 100644
> --- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
> +++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
> @@ -111,7 +111,7 @@ static int cdn_dp_clk_enable(struct cdn_dp_device *dp)
>   	ret = pm_runtime_get_sync(dp->dev);
>   	if (ret < 0) {
>   		DRM_DEV_ERROR(dp->dev, "cannot get pm runtime %d\n", ret);
> -		goto err_pclk;
> +		goto err_sync;

I think the name err_pm_runtime_get is better.
err_sync is not a clear name for the pm_runtime_get_sync.

>   	}
>   
>   	reset_control_assert(dp->core_rst);
> @@ -133,6 +133,7 @@ static int cdn_dp_clk_enable(struct cdn_dp_device *dp)
>   	return 0;
>   
>   err_set_rate:
> +err_sync:

miss pm_runtime_put, it should be:

err_set_rate:
     pm_runtime_put(dp->dev);
err_pm_runtime_get:
     clk_disable_unprepare(dp->core_clk);
err_core_clk:

>   	clk_disable_unprepare(dp->core_clk);
>   err_core_clk:
>   	clk_disable_unprepare(dp->pclk);


-- 
Ｍark Yao

Re: [PATCH] drm/rockchip: cdn-dp: Fix error handling

[Christophe JAILLET]

Le 20/02/2017 à 02:40, Mark yao a écrit :
> On 2017年02月20日 00:59, Christophe JAILLET wrote:
>> It is likely that both 'clk_disable_unprepare()' should be called if
>> 'pm_runtime_get_sync()' fails.
>>
>> Add a new label for that, because 'err_set_rate' is not meaningful in 
>> this
>> case.
>>
>>
>> Fixes: 1a0f7ed3abe2 ("drm/rockchip: cdn-dp: add cdn DP support for 
>> rk3399")
>>
>> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
>> ---
>> Not sure but a 'pm_runtime_get_sync()' is maybe also required in the
>> 'err_set_rate' path.
>> ---
>>   drivers/gpu/drm/rockchip/cdn-dp-core.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c 
>> b/drivers/gpu/drm/rockchip/cdn-dp-core.c
>> index 9ab67a670885..0fe1ec8b8fb1 100644
>> --- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
>> +++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
>> @@ -111,7 +111,7 @@ static int cdn_dp_clk_enable(struct cdn_dp_device 
>> *dp)
>>       ret = pm_runtime_get_sync(dp->dev);
>>       if (ret < 0) {
>>           DRM_DEV_ERROR(dp->dev, "cannot get pm runtime %d\n", ret);
>> -        goto err_pclk;
>> +        goto err_sync;
>
> I think the name err_pm_runtime_get is better.
> err_sync is not a clear name for the pm_runtime_get_sync.
>
I will change it.

>>       }
>>         reset_control_assert(dp->core_rst);
>> @@ -133,6 +133,7 @@ static int cdn_dp_clk_enable(struct cdn_dp_device 
>> *dp)
>>       return 0;
>>     err_set_rate:
>> +err_sync:
>
> miss pm_runtime_put, it should be:
>
I am wondering if 'pm_runtime_put_sync' should be added, instead.
We want to revert the 'pm_runtime_get_sync' of line 111. According to 
the naming of the function, the _sync version looks more logical to me.
Using ccoccinelle shows that 2/3 of functions calling both 
'pm_runtime_get_sync' and 'pm_runtime_get[_sync]' and using the _sync 
variant.

Which semantic is the correct one?


> err_set_rate:
>     pm_runtime_put(dp->dev);
> err_pm_runtime_get:
>     clk_disable_unprepare(dp->core_clk);
> err_core_clk:
>
>> clk_disable_unprepare(dp->core_clk);
>>   err_core_clk:
>>       clk_disable_unprepare(dp->pclk);
>
>

Re: [PATCH] drm/rockchip: cdn-dp: Fix error handling

[Mark yao]

On 2017年02月20日 14:41, Christophe JAILLET wrote:
> Le 20/02/2017 à 02:40, Mark yao a écrit :
>> On 2017年02月20日 00:59, Christophe JAILLET wrote:
>>> It is likely that both 'clk_disable_unprepare()' should be called if
>>> 'pm_runtime_get_sync()' fails.
>>>
>>> Add a new label for that, because 'err_set_rate' is not meaningful 
>>> in this
>>> case.
>>>
>>>
>>> Fixes: 1a0f7ed3abe2 ("drm/rockchip: cdn-dp: add cdn DP support for 
>>> rk3399")
>>>
>>> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
>>> ---
>>> Not sure but a 'pm_runtime_get_sync()' is maybe also required in the
>>> 'err_set_rate' path.
>>> ---
>>>   drivers/gpu/drm/rockchip/cdn-dp-core.c | 3 ++-
>>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c 
>>> b/drivers/gpu/drm/rockchip/cdn-dp-core.c
>>> index 9ab67a670885..0fe1ec8b8fb1 100644
>>> --- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
>>> +++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
>>> @@ -111,7 +111,7 @@ static int cdn_dp_clk_enable(struct 
>>> cdn_dp_device *dp)
>>>       ret = pm_runtime_get_sync(dp->dev);
>>>       if (ret < 0) {
>>>           DRM_DEV_ERROR(dp->dev, "cannot get pm runtime %d\n", ret);
>>> -        goto err_pclk;
>>> +        goto err_sync;
>>
>> I think the name err_pm_runtime_get is better.
>> err_sync is not a clear name for the pm_runtime_get_sync.
>>
> I will change it.
>
>>>       }
>>>         reset_control_assert(dp->core_rst);
>>> @@ -133,6 +133,7 @@ static int cdn_dp_clk_enable(struct 
>>> cdn_dp_device *dp)
>>>       return 0;
>>>     err_set_rate:
>>> +err_sync:
>>
>> miss pm_runtime_put, it should be:
>>
> I am wondering if 'pm_runtime_put_sync' should be added, instead.
> We want to revert the 'pm_runtime_get_sync' of line 111. According to 
> the naming of the function, the _sync version looks more logical to me.
> Using ccoccinelle shows that 2/3 of functions calling both 
> 'pm_runtime_get_sync' and 'pm_runtime_get[_sync]' and using the _sync 
> variant.
>

pm_runtime_get_sync will block until hardware actually done power configure,
we need make sure power is enable before use the hardware, So we should 
use pm_runtime_get_sync at power on.

At power off time, use pm_runtime_put is enough, it can be async, no 
need block.

Thanks.

> Which semantic is the correct one?
>
>
>> err_set_rate:
>>     pm_runtime_put(dp->dev);
>> err_pm_runtime_get:
>>     clk_disable_unprepare(dp->core_clk);
>> err_core_clk:
>>
>>> clk_disable_unprepare(dp->core_clk);
>>>   err_core_clk:
>>>       clk_disable_unprepare(dp->pclk);
>>
>>
>
>
>
>


-- 
Ｍark Yao