[PATCH v5 4/7] drm/bridge: dw-hdmi: Add API dw_hdmi_set_sample_iec958() for iec958 format

[Liu Ying]

On 09/10/2025, Shengjiu Wang wrote:
> Hi
> 
> On Tue, Sep 9, 2025 at 2:39 PM Maxime Ripard <mripard at kernel.org> wrote:
>>
>> Hi,
>>
>> On Wed, Sep 03, 2025 at 06:41:05PM +0800, Shengjiu Wang wrote:
>>> On Tue, Sep 2, 2025 at 12:52 AM Luca Ceresoli <luca.ceresoli at bootlin.com> wrote:
>>>>
>>>> Hello Shengjiu,
>>>>
>>>> On Thu, 21 Aug 2025 15:31:28 +0800
>>>> Shengjiu Wang <shengjiu.wang at nxp.com> wrote:
>>>>
>>>>> Add API dw_hdmi_set_sample_iec958() for IEC958 format because audio device
>>>>> driver needs IEC958 information to configure this specific setting.
>>>>>
>>>>> Signed-off-by: Shengjiu Wang <shengjiu.wang at nxp.com>
>>>>> Acked-by: Liu Ying <victor.liu at nxp.com>
>>>>
>>>> [...]
>>>>
>>>>> +void dw_hdmi_set_sample_iec958(struct dw_hdmi *hdmi, unsigned int iec958)
>>>>> +{
>>>>> +     mutex_lock(&hdmi->audio_mutex);
>>>>> +     hdmi->sample_iec958 = iec958;
>>>>> +     mutex_unlock(&hdmi->audio_mutex);
>>>>> +}
>>>>
>>>> Apologies for jumping in the discussion as late as in v5, but I noticed
>>>> this patch and I was wondering whether this mutex_lock/unlock() is
>>>> really needed, as you're copying an int.
>>>
>>> Thanks for your comments.
>>>
>>> Seems it is not necessary to add mutex here. I just follow the code as
>>> other similar functions.  I will send a new version to update it.
>>
>> Let's not be smart about it. Next thing you know, someone will add
>> another field in there that would absolutely require a mutex and now
>> you're not race free anymore.
>>
>> Unless there's a real concern, the mutex must stay.
>>
> 
> Ok, thanks for comments.  Then Patch v6 need to be dropped.

To properly track the changelog with patchwork, can you send v7 to add
the mutex?

> 
> Is there any other comments for this Patch v5?
> If no, can this series be accepted?
> 
> Best regards
> Shengjiu Wang


-- 
Regards,
Liu Ying