[RFT PATCH v1 2/5] usb: Handle XACTERR error in DATA phase of USB storage

[Marek Vasut]

On 3/22/20 2:00 PM, Lukasz Majewski wrote:
> This change brings support for handling XACTERR error during DATA phase
> of USB BBB (bulk) transmission.
> 
> The fix is to clear stall'ed endpoint and reset recovery on the USB mass
> storage class.
> 
> 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"]
> ---
> 
>  common/usb_storage.c | 10 ++++++++++
>  include/usb_defs.h   |  1 +
>  2 files changed, 11 insertions(+)
> 
> diff --git a/common/usb_storage.c b/common/usb_storage.c
> index 097b6729c1..92e1e54d1c 100644
> --- a/common/usb_storage.c
> +++ b/common/usb_storage.c
> @@ -740,6 +740,16 @@ static int usb_stor_BBB_transport(struct scsi_cmd *srb, struct us_data *us)
>  
>  	result = usb_bulk_msg(us->pusb_dev, pipe, srb->pdata, srb->datalen,
>  			      &data_actlen, USB_CNTL_TIMEOUT * 5);
> +
> +	/* special handling of XACTERR in DATA phase */
> +	if (result < 0 && (us->pusb_dev->status & USB_ST_XACTERR)) {
> +		debug("XACTERR in data phase - clr, reset, and return fail.\n");
> +		usb_stor_BBB_clear_endpt_stall(us, dir_in ?
> +					       us->ep_in : us->ep_out);
> +		usb_stor_BBB_reset(us);
> +		return USB_STOR_TRANSPORT_FAILED;
> +	}
> +

Can resetting the endpoint result in data corruption of some sort here ?
Especially if this happens on filesystem write for example ?