Re: [PATCH v2] xhci: reduce xhci_handshake timeout in xhci_reset

Greg Kroah-Hartman
2022-02-14T12:29:18Z

On Mon, Feb 14, 2022 at 05:50:16PM +0530, Pavankumar Kondeti wrote:
> From: Daehwan Jung <dh10.jung@samsung.com>
>
> xhci_reset() is called with interrupts disabled. Waiting 10 seconds for
> controller reset and controller ready operations can be fatal to the
> system when controller is timed out. Reduce the timeout to 1 second
> and print a error message when the time out happens.
>
> Fixes: 22ceac191211 ("xhci: Increase reset timeout for Renesas 720201 host.")
> Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
> Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
> ---
>
> v2:
> - Add error print statements in the code that change log refers to
>
> drivers/usb/host/xhci.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index dc357ca..bb9ea3f 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -196,9 +196,11 @@ int xhci_reset(struct xhci_hcd *xhci)
> udelay(1000);
>
> ret = xhci_handshake(&xhci->op_regs->command,
> - CMD_RESET, 0, 10 * 1000 * 1000);
> - if (ret)
> + CMD_RESET, 0, 1 * 1000 * 1000);
> + if (ret) {
> + xhci_err(xhci, "Host controller reset timed out\n");

A timeout is not the only error that could have happened here. So why
claim that all errors are timeout errors?

How did you test this?

thanks,

greg k-h