> we do some scsi ops where we give a device a large buffer and expect
> it to only fill part of it because we dont know how big that part
> will be.
>
> the underrun handling in mpii always caused this to fail, so devices
> relying on this didnt work as expected (eg, ses).
>
> according to the solaris driver we only get underruns on ok scsi
> commands, so we dont have to check the NO_SCSI_STATUS bit, we can
> trust that its ok but with a residual calculation.
>
> tests please :)
Are you sure you don't want to /* FALLTHROUGH */ ?
It would probably be better to do something like
set xs->resid
if (NO_SCSI_STATUS)
xs->status = SCSI_OK; /* otherwise nonsensical value */
/* FALLTHROUGH */
instead.
> Index: mpii.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/pci/mpii.c,v
> retrieving revision 1.38
> diff -u -p -r1.38 mpii.c
> --- mpii.c 21 Feb 2011 09:36:15 -0000 1.38
> +++ mpii.c 21 Feb 2011 13:03:15 -0000
> @@ -4649,11 +4649,7 @@ mpii_scsi_cmd_done(struct mpii_ccb *ccb)
> switch (letoh16(sie->ioc_status) & MPII_IOCSTATUS_MASK) {
> case MPII_IOCSTATUS_SCSI_DATA_UNDERRUN:
> xs->resid = xs->datalen - letoh32(sie->transfer_count);
> - if (sie->scsi_state & MPII_SCSIIO_ERR_STATE_NO_SCSI_STATUS) {
> - xs->error = XS_DRIVER_STUFFUP;
> - break;
> - }
> - /* FALLTHROUGH */
> + break;
> case MPII_IOCSTATUS_SUCCESS:
> case MPII_IOCSTATUS_SCSI_RECOVERED_ERROR:
> switch (xs->status) {
