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

[Shengjiu Wang]

On Mon, Sep 22, 2025 at 11:01 AM Liu Ying <victor.liu at nxp.com> wrote:
>
> 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?

Yes, will send it.

Best regards

Shengjiu wang

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