[RFT PATCH v1 5/5] usb: Handle QT_TOKEN_STATUS_XACTERR error when sending data

[Marek Vasut]

On 3/22/20 2:00 PM, Lukasz Majewski wrote:
> This code adds check if QT_TOKEN_STATUS_XACTERR error occurred. When it is
> detected the token is reconfigured and transmission is retried.
> 
> This code is the port to newest U-Boot of the fix from - "rayvt" (from [1]).
> 
> Links:
> [1] - https://forum.doozan.com/read.php?3,35295,35295#msg-35295
> [2] - https://www.dropbox.com/s/nrkrd1no63viuu8/uboot-bodhi-2016.05-timeoutTD.patch?dl=0
> 
> 
> Signed-off-by: Lukasz Majewski <lukma at denx.de>
> [Unfortunately, the original patch [2] did not contain S-o-B from the original
> author - "rayvt"]
> ---
> 
>  drivers/usb/host/ehci-hcd.c | 27 ++++++++++++++++++++++++++-
>  1 file changed, 26 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
> index 0a77111f80..45eda7ad24 100644
> --- a/drivers/usb/host/ehci-hcd.c
> +++ b/drivers/usb/host/ehci-hcd.c
> @@ -315,6 +315,7 @@ ehci_submit_async(struct usb_device *dev, unsigned long pipe, void *buffer,
>  	int timeout;
>  	int ret = 0;
>  	struct ehci_ctrl *ctrl = ehci_get_ctrl(dev);
> +	int trynum;
>  
>  	debug("dev=%p, pipe=%lx, buffer=%p, length=%d, req=%p\n", dev, pipe,
>  	      buffer, length, req);
> @@ -560,6 +561,10 @@ ehci_submit_async(struct usb_device *dev, unsigned long pipe, void *buffer,
>  	ehci_writel(&ctrl->hcor->or_usbsts, (usbsts & 0x3f));
>  
>  	/* Enable async. schedule. */
> +	trynum = 1;	/* No more than 2 tries, in case of XACTERR. */
> +retry_xacterr:;
> +	vtd = &qtd[qtd_counter - 1];
> +
>  	cmd = ehci_readl(&ctrl->hcor->or_usbcmd);
>  	cmd |= CMD_ASE;
>  	ehci_writel(&ctrl->hcor->or_usbcmd, cmd);

Are you sure always retrying the transfer if you get XACTERR is the
right thing to do, even if you get that e.g. on filesystem writes ?