Re: [PATCH] usb: host: xhci: Do not re-initialize the XHCI HC if being removed

From: Sergey Shtylyov
Date: Tue May 23 2023 - 04:45:42 EST


Hello!

On 5/23/23 4:53 AM, Wesley Cheng wrote:

> During XHCI resume, if there was a host controller error detected the
> routine will attempt to re-initialize the XHCI HC, so that it can return
> back to an operational state. If the XHCI host controller is being
> removed, this sequence would be already handled within the XHCI halt path,
> leading to a duplicate set of reg ops/calls. In addition, since the XHCI
> bus is being removed, the overhead added in restarting the HCD is
> unnecessary. Check for the XHC state before setting the reinit_xhc
> parameter, which is responsible for triggering the restart.
>
> Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
> ---
> drivers/usb/host/xhci.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index b81313ffeb76..2017ed3ae4a7 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -1028,7 +1028,8 @@ int xhci_resume(struct xhci_hcd *xhci, pm_message_t msg)
> temp = readl(&xhci->op_regs->status);
>
> /* re-initialize the HC on Restore Error, or Host Controller Error */
> - if (temp & (STS_SRE | STS_HCE)) {
> + if ((temp & (STS_SRE | STS_HCE)) &&
> + !(xhci->xhc_state & XHCI_STATE_REMOVING)) {

Please add one more tab here in order not to blend it with the following lines.

> reinit_xhc = true;
> if (!xhci->broken_suspend)
> xhci_warn(xhci, "xHC error in resume, USBSTS 0x%x, Reinit\n", temp);

MBR, Sergey