From: Lalit Chandivade <lalit.chandivade@xxxxxxxxxx>
The current code would incorrectly return a DID_OK for a
CHECK CONDITION with Recovered error sense key causing incorrect
completion of a command when there is a dropped frame.
Signed-off-by: Lalit Chandivade <lalit.chandivade@xxxxxxxxxx>
Signed-off-by: Tej Parkash <tej.parkash@xxxxxxxxxx>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@xxxxxxxxxx>
---
drivers/scsi/qla4xxx/ql4_isr.c | 102 +++++++++++++++++++++++-----------------
1 files changed, 59 insertions(+), 43 deletions(-)
diff --git a/drivers/scsi/qla4xxx/ql4_isr.c b/drivers/scsi/qla4xxx/ql4_isr.c
index fc542a9..db8c8e5 100644
--- a/drivers/scsi/qla4xxx/ql4_isr.c
+++ b/drivers/scsi/qla4xxx/ql4_isr.c
@@ -243,56 +243,72 @@ static void qla4xxx_status_entry(struct scsi_qla_host *ha,
scsi_set_resid(cmd, residual);
- /*
- * If there is scsi_status, it takes precedense over
- * underflow condition.
- */
- if (scsi_status != 0) {
- cmd->result = DID_OK << 16 | scsi_status;
+ if (sts_entry->iscsiFlags & ISCSI_FLAG_RESIDUAL_UNDER) {
+
+ /* Both the firmware and target reported UNDERRUN:
+ *
+ * MID-LAYER UNDERFLOW case:
+ * Some kernels do not properly detect midlayer
+ * underflow, so we manually check it and return
+ * ERROR if the minimum required data was not
+ * received.
+ *
+ * ALL OTHER cases:
+ * Fall thru to check scsi_status
+ */
+ if (!scsi_status && (scsi_bufflen(cmd) - residual) <
+ cmd->underflow) {
+ DEBUG2(ql4_printk(KERN_INFO, ha,
+ "scsi%ld:%d:%d:%d: %s: Mid-layer Data underrun, xferlen = 0x%x,residual = 0x%x\n",
+ ha->host_no,
+ cmd->device->channel,
+ cmd->device->id,
+ cmd->device->lun, __func__,
+ scsi_bufflen(cmd),
+ residual));
- if (scsi_status != SCSI_CHECK_CONDITION)
+ cmd->result = DID_ERROR << 16;
break;
+ }
+
+ } else if (scsi_status != SAM_STAT_TASK_SET_FULL &&
+ scsi_status != SAM_STAT_BUSY) {
- /* Copy Sense Data into sense buffer. */
- qla4xxx_copy_sense(ha, sts_entry, srb);
- } else {
/*
- * If RISC reports underrun and target does not
- * report it then we must have a lost frame, so
- * tell upper layer to retry it by reporting a
- * bus busy.
+ * The firmware reports UNDERRUN, but the target does
+ * not report it:
+ *
+ * scsi_status | host_byte device_byte
+ * | (19:16) (7:0)
+ * ============= | ========= ===========
+ * TASK_SET_FULL | DID_OK scsi_status
+ * BUSY | DID_OK scsi_status
+ * ALL OTHERS | DID_ERROR scsi_status
+ *
+ * Note: If scsi_status is task set full or busy,
+ * then this else if would fall thru to check the
+ * scsi_status and return DID_OK.
*/
- if ((sts_entry->iscsiFlags &
- ISCSI_FLAG_RESIDUAL_UNDER) == 0) {
- cmd->result = DID_BUS_BUSY << 16;
- } else if ((scsi_bufflen(cmd) - residual) <
- cmd->underflow) {
- /*
- * Handle mid-layer underflow???
- *
- * For kernels less than 2.4, the driver must
- * return an error if an underflow is detected.
- * For kernels equal-to and above 2.4, the
- * mid-layer will appearantly handle the
- * underflow by detecting the residual count --
- * unfortunately, we do not see where this is
- * actually being done. In the interim, we
- * will return DID_ERROR.
- */
- DEBUG2(printk("scsi%ld:%d:%d:%d: %s: "
- "Mid-layer Data underrun1, "
- "xferlen = 0x%x, "
- "residual = 0x%x\n", ha->host_no,
- cmd->device->channel,
- cmd->device->id,
- cmd->device->lun, __func__,
- scsi_bufflen(cmd), residual));
- cmd->result = DID_ERROR << 16;
- } else {
- cmd->result = DID_OK << 16;
- }
+ DEBUG2(ql4_printk(KERN_INFO, ha,
+ "scsi%ld:%d:%d:%d: %s: Dropped frame(s) detected (0x%x of 0x%x bytes).\n",
+ ha->host_no,
+ cmd->device->channel,
+ cmd->device->id,
+ cmd->device->lun, __func__,
+ residual,
+ scsi_bufflen(cmd)));
+
+ cmd->result = DID_ERROR << 16 | scsi_status;
+ goto check_scsi_status;
}
+
+ cmd->result = DID_OK << 16 | scsi_status;
+
+check_scsi_status:
+ if (scsi_status == SAM_STAT_CHECK_CONDITION)
+ qla4xxx_copy_sense(ha, sts_entry, srb);
+
break;
case SCS_DEVICE_LOGGED_OUT:
--
1.7.8.GIT
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