RE: [PATCH 06/17] hpsa: retry driver initiated commands on busy status

["Shergill, Gurinder" <gurinder.shergill@hp.com>]

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| -----Original Message-----
| From: linux-scsi-owner@vger.kernel.org [mailto:linux-scsi-
| owner@vger.kernel.org] On Behalf Of Stephen M. Cameron
| Sent: Friday, April 20, 2012 8:07 AM
| To: james.bottomley@hansenpartnership.com
| Cc: linux-scsi@vger.kernel.org; linux-kernel@vger.kernel.org; Gates, Matt;
| stephenmcameron@gmail.com; thenzl@redhat.com; akpm@linux-foundation.org;
| mikem@beardog.cce.hp.com
| Subject: [PATCH 06/17] hpsa: retry driver initiated commands on busy
| status
| 
| From: Matt Bondurant <Matthew.dav.bondurant@hp.com>
| 
| In shared SAS configurations we might get a busy status during driver
| initiated commands (e.g. during rescan for devices).  We should retry the
| command in such cases rather than giving up.

This may or may not apply to your situation. Some targets/disks return TASK SET FULL when they can't accept any new SCSI commands. If that applies to your situation, it may make sense to also check for SCSI status of SAM_STAT_TASK_SET_FULL.

Sunny

| 
| Signed-off-by: Matt Bondurant <Matthew.dav.bondurant@hp.com>
| Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
| ---
|  drivers/scsi/hpsa.c |   12 +++++++++++-
|  1 files changed, 11 insertions(+), 1 deletions(-)
| 
| diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index
| fcb9fb2..7355891 100644
| --- a/drivers/scsi/hpsa.c
| +++ b/drivers/scsi/hpsa.c
| @@ -234,6 +234,15 @@ static int check_for_unit_attention(struct ctlr_info
| *h,
|  	return 1;
|  }
| 
| +static int check_for_busy(struct ctlr_info *h, struct CommandList *c) {
| +	if (c->err_info->CommandStatus != CMD_TARGET_STATUS ||
| +		c->err_info->ScsiStatus != SAM_STAT_BUSY)
| +		return 0;
| +	dev_warn(&h->pdev->dev, HPSA "device busy");
| +	return 1;
| +}
| +
|  static ssize_t host_store_rescan(struct device *dev,
|  				 struct device_attribute *attr,
|  				 const char *buf, size_t count)
| @@ -1379,7 +1388,8 @@ static void
| hpsa_scsi_do_simple_cmd_with_retry(struct ctlr_info *h,
|  		memset(c->err_info, 0, sizeof(*c->err_info));
|  		hpsa_scsi_do_simple_cmd_core(h, c);
|  		retry_count++;
| -	} while (check_for_unit_attention(h, c) && retry_count <= 3);
| +	} while ((check_for_unit_attention(h, c) ||
| +			check_for_busy(h, c)) && retry_count <= 3);
|  	hpsa_pci_unmap(h->pdev, c, 1, data_direction);  }
| 
| 
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