On Thu, 2015-09-10 at 22:16 +0000, Himanshu Madhani wrote: > Hi Nic, > > Sorry about the delay in response. > > I have tested with RHEL 6.5 and noticed that IO were not able to complete > with 16M and 32M read/write. IO¹s were getting error due to Mid-layer > underflow > > With initiator running upstream kernel version 4.2 as well I was seeing > error with Mid-layer reporting under-run. > > I made change in the driver to report DID_OK to Mid-layer with residual > count and I was able to see IO completed without any error. > Basically, overriding driver¹s logic of failing an I/O, when residual > makes it an error with scsi_cmnd->underflow set. > In reality, though, with scsi_cmnd->underflow being set, Linux Qlogic > initiator will always see this as an error. > Maybe this is useful in other OSes. We have verified both read and write > data on FC trace and it looks good. > Great. Thanks for the update. > Here¹s diff that was done in qla2xxx driver to report response to > mid-layer as DID_OK. > > > # git diff > diff --git a/drivers/scsi/qla2xxx/qla_isr.c > b/drivers/scsi/qla2xxx/qla_isr.c > index ccf6a7f..fc7b6a2 100644 > --- a/drivers/scsi/qla2xxx/qla_isr.c > +++ b/drivers/scsi/qla2xxx/qla_isr.c > @@ -2257,7 +2257,7 @@ qla2x00_status_entry(scsi_qla_host_t *vha, struct > rsp_que *rsp, void *pkt) > "detected (0x%x of 0x%x bytes).\n", > resid, scsi_bufflen(cp)); > > - res = DID_ERROR << 16; > + res = DID_OK << 16; > break; > } > } else if (lscsi_status != SAM_STAT_TASK_SET_FULL && > (END) > > > Please go ahead and add patch to mainline kernel. > This missed the last linux-next build by a day, but with your Tested-by + Signed-off-by on this patch, I think it's still safe enough to queue for v4.3-rc1 code. (Adding JEJB CC') qla2xxx: Allow DID_OK status for residual under/overflow completion https://git.kernel.org/cgit/linux/kernel/git/nab/target-pending.git/commit/?h=for-next&id=46376bdc1e8a77c6d2cc65b77a1e340d4b4c9f1c The target-pending/for-next PULL request will be going out in the next 48 hours. Please let me know ASAP if you hit any regressions. Thank you, --nab -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
