sys/dev/pci/mpii.c: revision 1.30
Fixes for PR kern/57133:
I can now explain why this assert is firing and have a fix for it. It is a regression introduced in R1.22 of mpii.c.
If a request comes in and the IOC returns a MPII_SCSIIO_STATUS_CHECK_COND condition, after
a successful transfer, or one that is a recovered error,
mpii(4) correctly sets the xs->error to XS_SENSE, but incorrectly sets xs->resid to 0 before
returning the xfer to the upper scsi layers. Once the upper layers get it, they notice the
XS_SENSE check condition and because it's a retryable error, they increment xs_requeuecnt, set
ERESTART and send the xfer request down to the mpii(4) layer again for a retry. What they do
not do is reset xs->resid equal to xs->datalen. When the xfer comes down to mpii(4) again, the
assert happens. The fix is for the mpii(4) driver to leave xs->resid alone when it encounters
a MPII_SCSIIO_STATUS_CHECK_COND condition.
This bug affects NetBSD-10, netbsd-9 and netbsd-8.
d16ec04f8a