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

[Frank Li]

> -----Original Message-----
> From: Peter Chen <hzpeterchen@xxxxxxxxx>
> Sent: Thursday, October 20, 2022 8:52 PM
> To: Frank Li <frank.li@xxxxxxx>
> Cc: imx@xxxxxxxxxxxxxxx; Pawel Laszczak <pawell@xxxxxxxxxxx>; Peter Chen
> <peter.chen@xxxxxxxxxx>; Roger Quadros <rogerq@xxxxxxxxxx>; Aswath
> Govindraju <a-govindraju@xxxxxx>; Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx>; open list:CADENCE USBSSP DRD IP DRIVER
> <linux-usb@xxxxxxxxxxxxxxx>; open list <linux-kernel@xxxxxxxxxxxxxxx>;
> stable@xxxxxxxxxx
> Subject: [EXT] Re: [PATCH 1/1] usb: cdns3: host: fix endless superspeed hub
> port reset
> 
> Caution: EXT Email
> 
> On Wed, Oct 19, 2022 at 11:21 PM Frank Li <Frank.Li@xxxxxxx> wrote:
> >
> > 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/power/runtime_status
> >
> >  suspended
> >
> >  cat /sys/bus/platform/devices/5b110000.usb/5b130000.usb/xhci-
> hcd.1.auto/usb1/power/runtime_status
> >
> >  active
> >
> >  cat /sys/bus/platform/devices/5b110000.usb/5b130000.usb/xhci-
> hcd.1.auto/power/runtime_status
> >
> >  active
> >
> >  cat
> /sys/bus/platform/devices/5b110000.usb/5b130000.usb/power/runtime_st
> atus
> >
> >  active
> >
> > So xhci_cdns3_suspend_quirk() have not called. U3 configure is not applied.
> >
> > move U3 configure into host start
> >
> > Signed-off-by: Li Jun <jun.li@xxxxxxx>
> > Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> > ---
> >  drivers/usb/cdns3/host.c | 58 +++++++++++++++++++++-------------------
> >  1 file changed, 31 insertions(+), 27 deletions(-)
> >
> > diff --git a/drivers/usb/cdns3/host.c b/drivers/usb/cdns3/host.c
> > index 9643b905e2d8..9092b6f4d7c4 100644
> > --- a/drivers/usb/cdns3/host.c
> > +++ b/drivers/usb/cdns3/host.c
> > @@ -24,11 +24,41 @@
> >  #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_suspend_quirk(struct usb_hcd *hcd)
> > +{
> > +       if (pm_runtime_status_suspended(hcd->self.controller))
> > +               return 0;
> > +
> > +       xhci_cdns3_plat_start(hcd);
> > +
> 
> Why does it need to call again at suspend?

[Frank Li] Power may lost at suspend. 

> 
> Peter
> 
> > +       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,
> >  };
> >
> >  static int __cdns_host_init(struct cdns *cdns)
> > @@ -90,32 +120,6 @@ 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);
> > --
> > 2.34.1
> >