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

[Lukasz Majewski]

Hi Marek,

> 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 ?

Please correct me if I'm wrong, but this code is executed when we do
receive data, not writing them. Those operations shall (and are?)
orthogonal.

> Especially if this happens on filesystem write for example ?

Do we write data here?


Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma at denx.de
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