[PATCH 18/18] mpi3mr: split off bus_reset function from host_reset

[Hannes Reinecke <hare@suse.de>]

SCSI EH host reset is the final callback in the escalation chain;
once we reach this we need to reset the controller.
As such it defeats the purpose to skip controller reset if no
I/Os are pending and the RAID device is to be reset; especially
after kexec there might be stale commands pending in firmware
for which we have no reference whatsoever.
So this patch splits off the check for pending I/O into a
'bus_reset' function, and leaves the actual controller reset
to the host reset.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sathya Prakash Veerichetty <sathya.prakash@broadcom.com>
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
---
 drivers/scsi/mpi3mr/mpi3mr_os.c | 57 +++++++++++++++++++++------------
 1 file changed, 37 insertions(+), 20 deletions(-)

diff --git a/drivers/scsi/mpi3mr/mpi3mr_os.c b/drivers/scsi/mpi3mr/mpi3mr_os.c
index 89ba015c5d7e..040031eb0c12 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_os.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_os.c
@@ -4012,20 +4012,45 @@ static inline void mpi3mr_setup_divert_ws(struct mpi3mr_ioc *mrioc,
  * mpi3mr_eh_host_reset - Host reset error handling callback
  * @scmd: SCSI command reference
  *
- * Issue controller reset if the scmd is for a Physical Device,
- * if the scmd is for RAID volume, then wait for
- * MPI3MR_RAID_ERRREC_RESET_TIMEOUT and checke whether any
- * pending I/Os prior to issuing reset to the controller.
+ * Issue controller reset
  *
  * Return: SUCCESS of successful reset else FAILED
  */
 static int mpi3mr_eh_host_reset(struct scsi_cmnd *scmd)
+{
+	struct mpi3mr_ioc *mrioc = shost_priv(scmd->device->host);
+	int retval = FAILED, ret;
+
+	ret = mpi3mr_soft_reset_handler(mrioc,
+	    MPI3MR_RESET_FROM_EH_HOS, 1);
+	if (ret)
+		goto out;
+
+	retval = SUCCESS;
+out:
+	sdev_printk(KERN_INFO, scmd->device,
+	    "Host reset is %s for scmd(%p)\n",
+	    ((retval == SUCCESS) ? "SUCCESS" : "FAILED"), scmd);
+
+	return retval;
+}
+
+/**
+ * mpi3mr_eh_bus_reset - Bus reset error handling callback
+ * @scmd: SCSI command reference
+ *
+ * Checks whether pending I/Os are present for the RAID volume;
+ * if not there's no need to reset the adapter.
+ *
+ * Return: SUCCESS of successful reset else FAILED
+ */
+static int mpi3mr_eh_bus_reset(struct scsi_cmnd *scmd)
 {
 	struct mpi3mr_ioc *mrioc = shost_priv(scmd->device->host);
 	struct mpi3mr_stgt_priv_data *stgt_priv_data;
 	struct mpi3mr_sdev_priv_data *sdev_priv_data;
 	u8 dev_type = MPI3_DEVICE_DEVFORM_VD;
-	int retval = FAILED, ret;
+	int retval = FAILED;
 
 	sdev_priv_data = scmd->device->hostdata;
 	if (sdev_priv_data && sdev_priv_data->tgt_priv_data) {
@@ -4035,25 +4060,16 @@ static int mpi3mr_eh_host_reset(struct scsi_cmnd *scmd)
 
 	if (dev_type == MPI3_DEVICE_DEVFORM_VD) {
 		mpi3mr_wait_for_host_io(mrioc,
-		    MPI3MR_RAID_ERRREC_RESET_TIMEOUT);
-		if (!mpi3mr_get_fw_pending_ios(mrioc)) {
+			MPI3MR_RAID_ERRREC_RESET_TIMEOUT);
+		if (!mpi3mr_get_fw_pending_ios(mrioc))
 			retval = SUCCESS;
-			goto out;
-		}
 	}
+	if (retval == FAILED)
+		mpi3mr_print_pending_host_io(mrioc);
 
-	mpi3mr_print_pending_host_io(mrioc);
-	ret = mpi3mr_soft_reset_handler(mrioc,
-	    MPI3MR_RESET_FROM_EH_HOS, 1);
-	if (ret)
-		goto out;
-
-	retval = SUCCESS;
-out:
 	sdev_printk(KERN_INFO, scmd->device,
-	    "Host reset is %s for scmd(%p)\n",
-	    ((retval == SUCCESS) ? "SUCCESS" : "FAILED"), scmd);
-
+		"Bus reset is %s for scmd(%p)\n",
+		((retval == SUCCESS) ? "SUCCESS" : "FAILED"), scmd);
 	return retval;
 }
 
@@ -4900,6 +4916,7 @@ static const struct scsi_host_template mpi3mr_driver_template = {
 	.change_queue_depth		= mpi3mr_change_queue_depth,
 	.eh_device_reset_handler	= mpi3mr_eh_dev_reset,
 	.eh_target_reset_handler	= mpi3mr_eh_target_reset,
+	.eh_bus_reset_handler		= mpi3mr_eh_bus_reset,
 	.eh_host_reset_handler		= mpi3mr_eh_host_reset,
 	.bios_param			= mpi3mr_bios_param,
 	.map_queues			= mpi3mr_map_queues,
-- 
2.35.3