[PATCH v2 08/10] drm/bridge: anx7625: enable HPD interrupts

[Dmitry Baryshkov]

On Fri, Mar 21, 2025 at 02:36:21AM +0530, Ayushi Makhija wrote:
> On 3/11/2025 9:09 PM, Dmitry Baryshkov wrote:
> > On Tue, Mar 11, 2025 at 05:54:43PM +0530, Ayushi Makhija wrote:
> >> When device enters the suspend state, it prevents
> >> HPD interrupts from occurring. To address this,
> >> add an additional PM runtime vote in hpd_enable().
> >> This vote is removed in hpd_disable().
> > 
> > Is it really enough to toggle the HPD interrupts? Is there any kind of
> > programming that should be moved to .hpd_enable() too (so that by
> > default the bridge doesn't generate HPD interrupts)?
> > 
> 
> Hi Dmirty,
> 
> I couldn't find the ANX7625 bridge driver datasheet, where all the registers information are present.
> 
> As per my understanding, we have anx7625_hpd_timer_config(), where debounce timer registers are getting set, which help to manage the detection and stability of the HPD signal.
> 
> anx7625_hpd_timer_config() is getting called from anx7625_runtime_pm_resume().
> 
> anx7625_runtime_pm_resume
>    anx7625_power_on_init
>        anx7625_ocm_loading_check
>            anx7625_disable_pd_protocol
>               anx7625_hpd_timer_config
> 
> So, I think HPD programming is already taken care in anx7625_hpd_timer_config(). anx7625_runtime_pm_resume() is getting called for both eDP and DP configuration. 
> 
> If you suggest then, I can move the anx7625_hpd_timer_config() from anx7625_disable_pd_protocol() to anx7625_bridge_hpd_enable().

This might result in HPD signal being generated after invalid or
improper timings. If we can't get a feedback from Analogix on how to
control HPD generation, then it's better to leave it as is.

-- 
With best wishes
Dmitry