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

From: Peter Chen
Date: Thu Oct 20 2022 - 21:52:39 EST


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_status
>
> 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?

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
>