Messages in this thread | | | Date | Sat, 26 Jun 2004 23:52:20 -0400 (EDT) | From | Alan Stern <> | Subject | Re: drivers/block/ub.c |
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On Sun, 27 Jun 2004, Oliver Neukum wrote:
> Am Samstag, 26. Juni 2004 22:06 schrieb Pete Zaitcev: > > +static int ub_submit_top_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd) > > +{ > > + struct ub_scsi_cmd *scmd; > > + > > + scmd = &sc->top_rqs_cmd; > > + > > + /* XXX Can be done at init */ > > + scmd->cdb[0] = REQUEST_SENSE; > > + scmd->cdb_len = 6; > > + scmd->dir = UB_DIR_READ; > > + scmd->state = UB_CMDST_INIT; > > + scmd->data = sc->top_sense; > > You must allocate a separate buffer to the sense data. > We had similar code in hid which leads to data corruption > on some architectures. It's an issue of DMA coherency.
I mentioned this some time ago to the SCSI maintainers. They felt that it wasn't necessary to allocate a separate buffer for the sense data -- I'm not sure why. Apparently most if not all SCSI drivers fail to do this. Usb-storage doesn't do it either; maybe we should.
Alan Stern
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