Re: [RFC 4/8] clk: qcom: gcc-sm8450: Keep usb30 prim gdsc on during runtime suspend

[Krishna Kurapati PSSNV]

On 10/19/2023 6:28 AM, Stephen Boyd wrote:
> Quoting Krishna Kurapati (2023-10-17 06:19:44)
> > When runtime suspend happens in host mode, if cable is removed at this
> > instant, it triggers a resume where a xhci register access is done when
> > gdsc is not on leading to a crash. Keep usb30 prim gdsc as on during
> > runtime suspend to avoid this crash.
> >
> > Signed-off-by: Krishna Kurapati <quic_kriskura@xxxxxxxxxxx>
> > ---
> > Note: I am not sure if this is the right way or setting GDSC flags to
> > PWRSTS_RET_ON is the right approach. So for now made this change to
>
> Does using PWRSTS_RET_ON work? Does the GDSC support being turned off or
> is the lowest power state retention?

I didn't see any issue when I put it as PWRSTS_RET_ON. If the GDSC is 
off, when we remove cable in host mode, we see a crash because of xhci 
register access. But when I try putting PWRSTS_RET_ON / 
CLK_RPM_ALWAYS_ON it doesn't crash.

Regard,
Krishna,