On Wed, Aug 07, 2024 at 01:13:52AM +0000, Thinh Nguyen wrote:
> On Fri, Jul 12, 2024, Frank Li wrote:
> > From: Li Jun <jun.li@xxxxxxx>
> >
> > The runtime resume will happen before system resume if system wakeup by
> > device mode wakeup event(e.g, VBUS). Add a flag to avoid init twice.
>
> What's the consequence of going through the resuming sequence twice?
> Will this cause any functional issue?
static int dwc3_core_init_for_resume(struct dwc3 *dwc)
{
...
ret = dwc3_clk_enable(dwc);
if (ret)
goto assert_reset;
...
}
clk will be enabled twice, the reference count in clk will be wrong because
clk_disable() only once at suspend.
So clk will be always ON at next suspend.
Frank Li
>
> Thanks,
> Thinh
>
> >
> > Reviewed-by: Peter Chen <peter.chen@xxxxxxx>
> > Signed-off-by: Li Jun <jun.li@xxxxxxx>
> > Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> > ---
> > drivers/usb/dwc3/core.c | 13 +++++++++++++
> > drivers/usb/dwc3/core.h | 1 +
> > 2 files changed, 14 insertions(+)
> >
> > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > index 734de2a8bd212..d60917fad8c52 100644
> > --- a/drivers/usb/dwc3/core.c
> > +++ b/drivers/usb/dwc3/core.c
> > @@ -950,6 +950,8 @@ static void dwc3_core_exit(struct dwc3 *dwc)
> > dwc3_phy_exit(dwc);
> > dwc3_clk_disable(dwc);
> > reset_control_assert(dwc->reset);
> > +
> > + dwc->core_inited = false;
> > }
> >
> > static bool dwc3_core_is_valid(struct dwc3 *dwc)
> > @@ -1446,6 +1448,8 @@ static int dwc3_core_init(struct dwc3 *dwc)
> > dwc3_writel(dwc->regs, DWC3_LLUCTL, reg);
> > }
> >
> > + dwc->core_inited = true;
> > +
> > return 0;
> >
> > err_power_off_phy:
> > @@ -2375,6 +2379,15 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
> >
> > switch (dwc->current_dr_role) {
> > case DWC3_GCTL_PRTCAP_DEVICE:
> > + /*
> > + * system resume may come after runtime resume
> > + * e.g. rpm suspend -> pm suspend -> wakeup
> > + * -> rpm resume -> system resume, so if already
> > + * runtime resumed, system resume should skip it.
> > + */
> > + if (dwc->core_inited)
> > + break;
> > +
> > ret = dwc3_core_init_for_resume(dwc);
> > if (ret)
> > return ret;
> > diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> > index 1e561fd8b86e2..8a4bfd9a25b19 100644
> > --- a/drivers/usb/dwc3/core.h
> > +++ b/drivers/usb/dwc3/core.h
> > @@ -1195,6 +1195,7 @@ struct dwc3 {
> > struct clk *utmi_clk;
> > struct clk *pipe_clk;
> >
> > + bool core_inited;
> > struct reset_control *reset;
> >
> > struct usb_phy *usb2_phy;
> >
> > --
> > 2.34.1
> >
