[PATCH] drm/bridge: analogix: Don't return -EINVAL when panel not support PSR in PSR functions

[PATCH] drm/bridge: analogix: Don't return -EINVAL when panel not support PSR in PSR functions

[zain wang]

We will ignored PSR setting if panel not support it. So, in this case, we should
return from analogix_dp_enable/disable_psr() without any error code.
Let's retrun 0 instead of -EINVAL when panel not support PSR in
analogix_dp_enable/disable_psr().

Signed-off-by: zain wang <wzz@rock-chips.com>
---
 drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index 6e0447f..0cb3695 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -112,7 +112,7 @@ int analogix_dp_enable_psr(struct device *dev)
 	struct edp_vsc_psr psr_vsc;
 
 	if (!dp->psr_support)
-		return -EINVAL;
+		return 0;
 
 	/* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
 	memset(&psr_vsc, 0, sizeof(psr_vsc));
@@ -135,7 +135,7 @@ int analogix_dp_disable_psr(struct device *dev)
 	struct edp_vsc_psr psr_vsc;
 
 	if (!dp->psr_support)
-		return -EINVAL;
+		return 0;
 
 	/* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
 	memset(&psr_vsc, 0, sizeof(psr_vsc));
@@ -878,6 +878,8 @@ static void analogix_dp_commit(struct analogix_dp_device *dp)
 	dp->psr_support = analogix_dp_detect_sink_psr(dp);
 	if (dp->psr_support)
 		analogix_dp_enable_sink_psr(dp);
+	else
+		dev_warn(dp->dev, "Sink not support PSR\n");
 }
 
 /*
-- 
1.9.1

Re: [PATCH] drm/bridge: analogix: Don't return -EINVAL when panel not support PSR in PSR functions

[Archit Taneja]

Hi,

On 12/02/2016 08:02 AM, zain wang wrote:
> We will ignored PSR setting if panel not support it. So, in this case, we should
> return from analogix_dp_enable/disable_psr() without any error code.
> Let's retrun 0 instead of -EINVAL when panel not support PSR in
> analogix_dp_enable/disable_psr().
>
> Signed-off-by: zain wang <wzz@rock-chips.com>
> ---
>  drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> index 6e0447f..0cb3695 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> @@ -112,7 +112,7 @@ int analogix_dp_enable_psr(struct device *dev)
>  	struct edp_vsc_psr psr_vsc;
>
>  	if (!dp->psr_support)
> -		return -EINVAL;
> +		return 0;

Looking at the rockchip analogix dp code, in analogix_dp_psr_set, the worker that calls
analogix_dp_enable/disable_psr isn't even if psr isn't enabled. So, the bridge funcs
shouldn't be called in the first place. I think the error handling is fine to have
here.

>
>  	/* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
>  	memset(&psr_vsc, 0, sizeof(psr_vsc));
> @@ -135,7 +135,7 @@ int analogix_dp_disable_psr(struct device *dev)
>  	struct edp_vsc_psr psr_vsc;
>
>  	if (!dp->psr_support)
> -		return -EINVAL;
> +		return 0;
>
>  	/* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
>  	memset(&psr_vsc, 0, sizeof(psr_vsc));
> @@ -878,6 +878,8 @@ static void analogix_dp_commit(struct analogix_dp_device *dp)
>  	dp->psr_support = analogix_dp_detect_sink_psr(dp);
>  	if (dp->psr_support)
>  		analogix_dp_enable_sink_psr(dp);
> +	else
> +		dev_warn(dp->dev, "Sink not support PSR\n");

This doesn't seem beneficial either. There seems to be a debug
print already in analogix_dp_detect_sink_psr which reports PSR
related info.

Archit

>  }
>
>  /*
>

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH] drm/bridge: analogix: Don't return -EINVAL when panel not support PSR in PSR functions

[Sean Paul]

On Thu, Dec 1, 2016 at 10:54 PM, Archit Taneja <architt@codeaurora.org> wrote:
> Hi,
>
> On 12/02/2016 08:02 AM, zain wang wrote:
>>
>> We will ignored PSR setting if panel not support it. So, in this case, we
>> should
>> return from analogix_dp_enable/disable_psr() without any error code.
>> Let's retrun 0 instead of -EINVAL when panel not support PSR in
>> analogix_dp_enable/disable_psr().
>>
>> Signed-off-by: zain wang <wzz@rock-chips.com>
>> ---
>>  drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 6 ++++--
>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> index 6e0447f..0cb3695 100644
>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> @@ -112,7 +112,7 @@ int analogix_dp_enable_psr(struct device *dev)
>>         struct edp_vsc_psr psr_vsc;
>>
>>         if (!dp->psr_support)
>> -               return -EINVAL;
>> +               return 0;
>
>
> Looking at the rockchip analogix dp code, in analogix_dp_psr_set, the worker
> that calls
> analogix_dp_enable/disable_psr isn't even if psr isn't enabled. So, the
> bridge funcs
> shouldn't be called in the first place. I think the error handling is fine
> to have
> here.
>

Hi Archit,

This was my first impression, too, and the complexity of the various
psr abstraction layers don't help :)

However, this code path will be hit if the source supports psr, but
the sink doesn't. The rockchip_drm_psr code doesn't know if the sink
supports psr, so it will end up calling this.

Sean


>>
>>         /* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
>>         memset(&psr_vsc, 0, sizeof(psr_vsc));
>> @@ -135,7 +135,7 @@ int analogix_dp_disable_psr(struct device *dev)
>>         struct edp_vsc_psr psr_vsc;
>>
>>         if (!dp->psr_support)
>> -               return -EINVAL;
>> +               return 0;
>>
>>         /* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
>>         memset(&psr_vsc, 0, sizeof(psr_vsc));
>> @@ -878,6 +878,8 @@ static void analogix_dp_commit(struct
>> analogix_dp_device *dp)
>>         dp->psr_support = analogix_dp_detect_sink_psr(dp);
>>         if (dp->psr_support)
>>                 analogix_dp_enable_sink_psr(dp);
>> +       else
>> +               dev_warn(dp->dev, "Sink not support PSR\n");
>
>
> This doesn't seem beneficial either. There seems to be a debug
> print already in analogix_dp_detect_sink_psr which reports PSR
> related info.
>
> Archit
>
>>  }
>>
>>  /*
>>
>
> --
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
> a Linux Foundation Collaborative Project

Re: [PATCH] drm/bridge: analogix: Don't return -EINVAL when panel not support PSR in PSR functions

[Archit Taneja]

On 12/02/2016 09:33 PM, Sean Paul wrote:
> On Thu, Dec 1, 2016 at 10:54 PM, Archit Taneja <architt@codeaurora.org> wrote:
>> Hi,
>>
>> On 12/02/2016 08:02 AM, zain wang wrote:
>>>
>>> We will ignored PSR setting if panel not support it. So, in this case, we
>>> should
>>> return from analogix_dp_enable/disable_psr() without any error code.
>>> Let's retrun 0 instead of -EINVAL when panel not support PSR in
>>> analogix_dp_enable/disable_psr().
>>>
>>> Signed-off-by: zain wang <wzz@rock-chips.com>
>>> ---
>>>  drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 6 ++++--
>>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>>> b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>>> index 6e0447f..0cb3695 100644
>>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>>> @@ -112,7 +112,7 @@ int analogix_dp_enable_psr(struct device *dev)
>>>         struct edp_vsc_psr psr_vsc;
>>>
>>>         if (!dp->psr_support)
>>> -               return -EINVAL;
>>> +               return 0;
>>
>>
>> Looking at the rockchip analogix dp code, in analogix_dp_psr_set, the worker
>> that calls
>> analogix_dp_enable/disable_psr isn't even if psr isn't enabled. So, the
>> bridge funcs
>> shouldn't be called in the first place. I think the error handling is fine
>> to have
>> here.
>>
>
> Hi Archit,
>
> This was my first impression, too, and the complexity of the various
> psr abstraction layers don't help :)
>
> However, this code path will be hit if the source supports psr, but
> the sink doesn't. The rockchip_drm_psr code doesn't know if the sink
> supports psr, so it will end up calling this.

Okay, thanks for the explanation. The dev_warn() below still seems
unnecessary, right?

Archit

>
> Sean
>
>
>>>
>>>         /* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
>>>         memset(&psr_vsc, 0, sizeof(psr_vsc));
>>> @@ -135,7 +135,7 @@ int analogix_dp_disable_psr(struct device *dev)
>>>         struct edp_vsc_psr psr_vsc;
>>>
>>>         if (!dp->psr_support)
>>> -               return -EINVAL;
>>> +               return 0;
>>>
>>>         /* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
>>>         memset(&psr_vsc, 0, sizeof(psr_vsc));
>>> @@ -878,6 +878,8 @@ static void analogix_dp_commit(struct
>>> analogix_dp_device *dp)
>>>         dp->psr_support = analogix_dp_detect_sink_psr(dp);
>>>         if (dp->psr_support)
>>>                 analogix_dp_enable_sink_psr(dp);
>>> +       else
>>> +               dev_warn(dp->dev, "Sink not support PSR\n");
>>
>>
>> This doesn't seem beneficial either. There seems to be a debug
>> print already in analogix_dp_detect_sink_psr which reports PSR
>> related info.
>>
>> Archit
>>
>>>  }
>>>
>>>  /*
>>>
>>
>> --
>> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
>> a Linux Foundation Collaborative Project

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH] drm/bridge: analogix: Don't return -EINVAL when panel not support PSR in PSR functions

[Sean Paul]

On Sun, Dec 4, 2016 at 10:13 PM, Archit Taneja <architt@codeaurora.org> wrote:
>
>
> On 12/02/2016 09:33 PM, Sean Paul wrote:
>>
>> On Thu, Dec 1, 2016 at 10:54 PM, Archit Taneja <architt@codeaurora.org>
>> wrote:
>>>
>>> Hi,
>>>
>>> On 12/02/2016 08:02 AM, zain wang wrote:
>>>>
>>>>
>>>> We will ignored PSR setting if panel not support it. So, in this case,
>>>> we
>>>> should
>>>> return from analogix_dp_enable/disable_psr() without any error code.
>>>> Let's retrun 0 instead of -EINVAL when panel not support PSR in
>>>> analogix_dp_enable/disable_psr().
>>>>
>>>> Signed-off-by: zain wang <wzz@rock-chips.com>
>>>> ---
>>>>  drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 6 ++++--
>>>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>>>> b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>>>> index 6e0447f..0cb3695 100644
>>>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>>>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>>>> @@ -112,7 +112,7 @@ int analogix_dp_enable_psr(struct device *dev)
>>>>         struct edp_vsc_psr psr_vsc;
>>>>
>>>>         if (!dp->psr_support)
>>>> -               return -EINVAL;
>>>> +               return 0;
>>>
>>>
>>>
>>> Looking at the rockchip analogix dp code, in analogix_dp_psr_set, the
>>> worker
>>> that calls
>>> analogix_dp_enable/disable_psr isn't even if psr isn't enabled. So, the
>>> bridge funcs
>>> shouldn't be called in the first place. I think the error handling is
>>> fine
>>> to have
>>> here.
>>>
>>
>> Hi Archit,
>>
>> This was my first impression, too, and the complexity of the various
>> psr abstraction layers don't help :)
>>
>> However, this code path will be hit if the source supports psr, but
>> the sink doesn't. The rockchip_drm_psr code doesn't know if the sink
>> supports psr, so it will end up calling this.
>
>
> Okay, thanks for the explanation. The dev_warn() below still seems
> unnecessary, right?
>

Yeah, one could make a case for dev_info (disclaimer: I have a high
tolerance for noisy logs), but a warning does seem excessive.

Sean

> Archit
>
>
>>
>> Sean
>>
>>
>>>>
>>>>         /* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
>>>>         memset(&psr_vsc, 0, sizeof(psr_vsc));
>>>> @@ -135,7 +135,7 @@ int analogix_dp_disable_psr(struct device *dev)
>>>>         struct edp_vsc_psr psr_vsc;
>>>>
>>>>         if (!dp->psr_support)
>>>> -               return -EINVAL;
>>>> +               return 0;
>>>>
>>>>         /* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
>>>>         memset(&psr_vsc, 0, sizeof(psr_vsc));
>>>> @@ -878,6 +878,8 @@ static void analogix_dp_commit(struct
>>>> analogix_dp_device *dp)
>>>>         dp->psr_support = analogix_dp_detect_sink_psr(dp);
>>>>         if (dp->psr_support)
>>>>                 analogix_dp_enable_sink_psr(dp);
>>>> +       else
>>>> +               dev_warn(dp->dev, "Sink not support PSR\n");
>>>
>>>
>>>
>>> This doesn't seem beneficial either. There seems to be a debug
>>> print already in analogix_dp_detect_sink_psr which reports PSR
>>> related info.
>>>
>>> Archit
>>>
>>>>  }
>>>>
>>>>  /*
>>>>
>>>
>>> --
>>> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
>>> a Linux Foundation Collaborative Project
>
>
> --
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
> a Linux Foundation Collaborative Project