Re: [PATCH] soc: qcom: pmic_glink_altmode: fix spurious DP hotplug events

From: Johan Hovold
Date: Wed Apr 02 2025 - 03:13:59 EST


On Tue, Apr 01, 2025 at 11:18:49AM -0700, Clayton Craft wrote:
> On 3/26/25 07:43, Johan Hovold wrote:
> > On Tue, Mar 25, 2025 at 09:32:10AM +0100, Johan Hovold wrote:

> >> I didn't realise you were also using a display/dock. Bjorn mentioned
> >> that he has noticed issues with one of his monitors (e.g. built-in hub
> >> reenumerating repeatedly iirc) which may be related.
>
> Sorry for the confusion, let me clarify:
>
> The original issue I reported to you on IRC was *without* a
> dock/external display attached, only a PD adapter was attached. With
> your patch, I no longer see these drm hotplug events in this scenario.
>
> After confirming that your patch resolved the spurious hotplug events
> when using a PD charger, I connected a dock+external display to see if
> the patch caused any regressions there for me. It was here that I
> noticed a periodic hotplug event firing 2 times every 30 seconds was
> still showing up. I don't know if this is expected or not, I've never
> noticed it before because I wasn't monitoring udev events.

Got it, thanks for clarifying.

Did you get a chance to try the patch enabling UCSI and USB-PD? That one
may possibly help with the dock issue:

https://lore.kernel.org/lkml/20250326124944.6338-1-johan+linaro@xxxxxxxxxx/

> >> Did it help with the display flickering too? Was that only on the
> >> external display?
>
> The flickering was only on the internal display, and your patch here
> seems to have resolved that.

Good. Is there any flickering on either screen when you see the spurious
HP events with the dock?

Johan