[PATCH 06/10] usb: chipidea: msm: keep the glue device runtime-active

[Manivannan Sadhasivam]

On Mon, Aug 10, 2026 at 06:42:10PM +0300, Dmitry Baryshkov wrote:
> The msm chipidea glue enables runtime PM with pm_runtime_no_callbacks()
> and nothing pinning it active. Right after a successful probe the
> driver core's pm_request_idle() runtime-suspends the glue (the ci core
> child has runtime PM disabled, so it does not hold its parent),

Why does the child's runtime PM disabled first of all?

> and
> when the glue sits in a power domain - the HSIC instances live in the
> USB_HS_HSIC GDSC on msm8974 - genpd then powers the domain off
> underneath the running controller. The EHCI register file reads back
> zeroes, an onboard hub's connect is never seen, and subsequent bus
> accesses into the unpowered block wedge the interconnect, eventually
> taking the whole SoC down.
> 
> Pin the glue runtime-active so the domain stays powered for the
> lifetime of the controller. Proper low-power handling can later be
> built on the child's runtime PM together with the HSIC wakeup
> interrupt.
> 

The commit message confuses between PM runtime 'active' and 'usage count'.
Marking a device as runtime PM 'active' wouldn't prevent it from being
suspended, but only increasing it's 'usage count' will. Which is what this patch
is doing btw, but just that the terminology is not correct.

- Mani

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