RE: [EXT] Re: [PATCH v2 1/1] usb: cdns3: host: fix endless superspeed hub port reset

[Frank Li]

> -----Original Message-----
> From: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
> Sent: Thursday, October 27, 2022 2:06 AM
> To: Frank Li <frank.li@xxxxxxx>
> Cc: Jun Li <jun.li@xxxxxxx>; Frank Li <frank.li@xxxxxxx>; a-
> govindraju@xxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; hzpeterchen@xxxxxxxxx;
> imx@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-
> usb@xxxxxxxxxxxxxxx; pawell@xxxxxxxxxxx; peter.chen@xxxxxxxxxx;
> rogerq@xxxxxxxxxx; stable@xxxxxxxxxx
> Subject: [EXT] Re: [PATCH v2 1/1] usb: cdns3: host: fix endless superspeed
> hub port reset
> 
> Caution: EXT Email
> 
> Am Mittwoch, 26. Oktober 2022, 21:07:49 CEST schrieb Frank Li:
> > From: Li Jun <jun.li@xxxxxxx>
> >
> > When usb 3.0 hub connect with one USB 2.0 device and NO USB 3.0 device,
> > some usb hub reports endless port reset message.
> >
> > [  190.324169] usb 2-1: new SuperSpeed USB device number 88 using xhci-
> hcd
> > [  190.352834] hub 2-1:1.0: USB hub found
> > [  190.356995] hub 2-1:1.0: 4 ports detected
> > [  190.700056] usb 2-1: USB disconnect, device number 88
> > [  192.472139] usb 2-1: new SuperSpeed USB device number 89 using xhci-
> hcd
> > [  192.500820] hub 2-1:1.0: USB hub found
> > [  192.504977] hub 2-1:1.0: 4 ports detected
> > [  192.852066] usb 2-1: USB disconnect, device number 89
> >
> > The reason is the runtime pm state of USB2.0 port is active and
> > USB 3.0 port is suspend, so parent device is active state.
> >
> >  cat
> > /sys/bus/platform/devices/5b110000.usb/5b130000.usb/xhci-
> hcd.1.auto/usb2/po
> > wer/runtime_status
> >
> >  suspended
> >
> >  cat
> > /sys/bus/platform/devices/5b110000.usb/5b130000.usb/xhci-
> hcd.1.auto/usb1/po
> > wer/runtime_status
> >
> >  active
> >
> >  cat
> > /sys/bus/platform/devices/5b110000.usb/5b130000.usb/xhci-
> hcd.1.auto/power/r
> > untime_status
> >
> >  active
> >
> >  cat
> >
> /sys/bus/platform/devices/5b110000.usb/5b130000.usb/power/runtime_sta
> tus
> >
> >  active
> >
> > So xhci_cdns3_suspend_quirk() have not called. U3 configure is not applied.
> >
> > move U3 configure into host start. Reinit again in resume function in case
> > controller power lost during suspend.
> >
> > Cc: stable@xxxxxxxxxxxxxxx 5.10
> > Signed-off-by: Li Jun <jun.li@xxxxxxx>
> > Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> > ---

[Frank Li] @greg, friendly ping.

> >
> > Change from V1 to V2.
> >  - call xhci_cdns3_plat_start() in xhci_cdns3_resume_quirk
> > in case power lost during suspend
> >
> >  drivers/usb/cdns3/host.c | 56 ++++++++++++++++++++--------------------
> >  1 file changed, 28 insertions(+), 28 deletions(-)
> >
> > diff --git a/drivers/usb/cdns3/host.c b/drivers/usb/cdns3/host.c
> > index 9643b905e2d8..6164fc4c96a4 100644
> > --- a/drivers/usb/cdns3/host.c
> > +++ b/drivers/usb/cdns3/host.c
> > @@ -24,11 +24,37 @@
> >  #define CFG_RXDET_P3_EN              BIT(15)
> >  #define LPM_2_STB_SWITCH_EN  BIT(25)
> >
> > -static int xhci_cdns3_suspend_quirk(struct usb_hcd *hcd);
> > +static void xhci_cdns3_plat_start(struct usb_hcd *hcd)
> > +{
> > +     struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> > +     u32 value;
> > +
> > +     /* set usbcmd.EU3S */
> > +     value = readl(&xhci->op_regs->command);
> > +     value |= CMD_PM_INDEX;
> > +     writel(value, &xhci->op_regs->command);
> > +
> > +     if (hcd->regs) {
> > +             value = readl(hcd->regs + XECP_AUX_CTRL_REG1);
> > +             value |= CFG_RXDET_P3_EN;
> > +             writel(value, hcd->regs + XECP_AUX_CTRL_REG1);
> > +
> > +             value = readl(hcd->regs + XECP_PORT_CAP_REG);
> > +             value |= LPM_2_STB_SWITCH_EN;
> > +             writel(value, hcd->regs + XECP_PORT_CAP_REG);
> > +     }
> > +}
> > +
> > +static int xhci_cdns3_resume_quirk(struct usb_hcd *hcd)
> > +{
> > +     xhci_cdns3_plat_start(hcd);
> > +     return 0;
> > +}
> >
> >  static const struct xhci_plat_priv xhci_plat_cdns3_xhci = {
> >       .quirks = XHCI_SKIP_PHY_INIT | XHCI_AVOID_BEI,
> > -     .suspend_quirk = xhci_cdns3_suspend_quirk,
> > +     .plat_start = xhci_cdns3_plat_start,
> > +     .resume_quirk = xhci_cdns3_resume_quirk,
> >  };
> >
> >  static int __cdns_host_init(struct cdns *cdns)
> > @@ -90,32 +116,6 @@ static int __cdns_host_init(struct cdns *cdns)
> >       return ret;
> >  }
> >
> > -static int xhci_cdns3_suspend_quirk(struct usb_hcd *hcd)
> > -{
> > -     struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> > -     u32 value;
> > -
> > -     if (pm_runtime_status_suspended(hcd->self.controller))
> > -             return 0;
> > -
> > -     /* set usbcmd.EU3S */
> > -     value = readl(&xhci->op_regs->command);
> > -     value |= CMD_PM_INDEX;
> > -     writel(value, &xhci->op_regs->command);
> > -
> > -     if (hcd->regs) {
> > -             value = readl(hcd->regs + XECP_AUX_CTRL_REG1);
> > -             value |= CFG_RXDET_P3_EN;
> > -             writel(value, hcd->regs + XECP_AUX_CTRL_REG1);
> > -
> > -             value = readl(hcd->regs + XECP_PORT_CAP_REG);
> > -             value |= LPM_2_STB_SWITCH_EN;
> > -             writel(value, hcd->regs + XECP_PORT_CAP_REG);
> > -     }
> > -
> > -     return 0;
> > -}
> > -
> >  static void cdns_host_exit(struct cdns *cdns)
> >  {
> >       kfree(cdns->xhci_plat_data);
> 
> Although I could only test it on v5.15 downstream kernel
> Acked-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
> 
>