Re: [PATCH 06/10] usb: chipidea: msm: keep the glue device runtime-active
Konrad Dybcio <[email protected]>
| Newsgroups | org.kernel.vger.linux-gpio,org.infradead.lists.linux-phy,org.kernel.vger.linux-arm-msm,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel,org.kernel.vger.linux-usb |
|---|---|
| Message-ID | <[email protected]> |
On 8/10/26 5:42 PM, 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), 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.
>
> Fixes: 2d0cdcc5a0e4 ("USB: gadget: Implement runtime PM for MSM bus glue driver")
> Assisted-by: Claude:claude-fable-5
> Signed-off-by: Dmitry Baryshkov <[email protected]>
> ---
FWIW downstream seems to implement "real" runpm, so perhaps your
agent can have some fun with that
Reviewed-by: Konrad Dybcio <[email protected]>
Konrad