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

From: Ayushi Makhija
Date: Thu Mar 20 2025 - 17:07:10 EST


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().

Thanks,
Ayushi