Re: [PATCH v6] xhci: re-initialize the HC during resume if HCE was set

[Puma Hsu]

On Thu, Feb 3, 2022 at 3:11 AM Mathias Nyman
<mathias.nyman@xxxxxxxxxxxxxxx> wrote:
>
> On 29.1.2022 11.30, Puma Hsu wrote:
> > When HCE(Host Controller Error) is set, it means an internal
> > error condition has been detected. Software needs to re-initialize
> > the HC, so add this check in xhci resume.
> >
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Puma Hsu <pumahsu@xxxxxxxxxx>
> > ---
> > v2: Follow Sergey Shtylyov <s.shtylyov@xxxxxx>'s comment.
> > v3: Add stable@xxxxxxxxxxxxxxx for stable release.
> > v4: Refine the commit message.
> > v5: Add a debug log. Follow Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>'s comment.
> > v6: Fix the missing declaration for str.
> >
> >  drivers/usb/host/xhci.c | 7 +++++--
> >  1 file changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> > index dc357cabb265..6f1198068004 100644
> > --- a/drivers/usb/host/xhci.c
> > +++ b/drivers/usb/host/xhci.c
> > @@ -1091,6 +1091,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
> >       int                     retval = 0;
> >       bool                    comp_timer_running = false;
> >       bool                    pending_portevent = false;
> > +     char                    str[XHCI_MSG_MAX];
> >
> >       if (!hcd->state)
> >               return 0;
> > @@ -1146,8 +1147,10 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
> >               temp = readl(&xhci->op_regs->status);
> >       }
> >
> > -     /* If restore operation fails, re-initialize the HC during resume */
> > -     if ((temp & STS_SRE) || hibernated) {
> > +     /* If restore operation fails or HC error is detected, re-initialize the HC during resume */
> > +     if ((temp & (STS_SRE | STS_HCE)) || hibernated) {
> > +             xhci_warn(xhci, "re-initialize HC during resume, USBSTS:%s\n",
> > +                       xhci_decode_usbsts(str, temp));
> >
> >               if ((xhci->quirks & XHCI_COMP_MODE_QUIRK) &&
> >                               !(xhci_all_ports_seen_u0(xhci))) {
> >
>
> Ended up modifying this patch a bit more than I first intended,
> - don't print warning in hibernation case, only error.
> - maybe using a lot of stack for a debug string isn't really needed.
> - make sure we read the usbsts register before checking for the HCE bit.
>
> Does the below work for you? If yes, and you agree I'll apply it instead

Hi Mathias,
Yes, your patch works for me, thanks!
Will you submit a new patch? or should I update to a new version?
Thanks.

> ---
>
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index dc357cabb265..04ec2de158bf 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -1091,6 +1091,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
>         int                     retval = 0;
>         bool                    comp_timer_running = false;
>         bool                    pending_portevent = false;
> +       bool                    reinit_xhc = false;
>
>         if (!hcd->state)
>                 return 0;
> @@ -1107,10 +1108,11 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
>         set_bit(HCD_FLAG_HW_ACCESSIBLE, &xhci->shared_hcd->flags);
>
>         spin_lock_irq(&xhci->lock);
> -       if ((xhci->quirks & XHCI_RESET_ON_RESUME) || xhci->broken_suspend)
> -               hibernated = true;
>
> -       if (!hibernated) {
> +       if (hibernated || xhci->quirks & XHCI_RESET_ON_RESUME || xhci->broken_suspend)
> +               reinit_xhc = true;
> +
> +       if (!reinit_xhc) {
>                 /*
>                  * Some controllers might lose power during suspend, so wait
>                  * for controller not ready bit to clear, just as in xHC init.
> @@ -1143,12 +1145,17 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
>                         spin_unlock_irq(&xhci->lock);
>                         return -ETIMEDOUT;
>                 }
> -               temp = readl(&xhci->op_regs->status);
>         }
>
> -       /* If restore operation fails, re-initialize the HC during resume */
> -       if ((temp & STS_SRE) || hibernated) {
> +       temp = readl(&xhci->op_regs->status);
> +
> +       /* re-initialize the HC on Restore Error, or Host Controller Error */
> +       if (temp & (STS_SRE | STS_HCE)) {
> +               reinit_xhc = true;
> +               xhci_warn(xhci, "xHC error in resume, USBSTS 0x%x, Reinit\n", temp);
> +       }
>
> +       if (reinit_xhc) {
>                 if ((xhci->quirks & XHCI_COMP_MODE_QUIRK) &&
>                                 !(xhci_all_ports_seen_u0(xhci))) {
>                         del_timer_sync(&xhci->comp_mode_recovery_timer);
>