Commit 5cd3bbfa authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by James Bottomley
Browse files

[SCSI] retry with missing data for INQUIRY



This patch changes scsi_probe_lun() to retry INQUIRY if the device has
not actually sent back any INQUIRY data,

This enables the Thecus N2050 storage device to work better. The
firmware on that device starts up strangely; it sends no data in
response to the initial INQUIRY, and it sends the INQUIRY information
in response to the followup REQUEST SENSE. But after that it works
better, so retrying the INQUIRY is enough to get it going.
Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent f4f4e47e
......@@ -573,6 +573,8 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
/* Each pass gets up to three chances to ignore Unit Attention */
for (count = 0; count < 3; ++count) {
int resid;
memset(scsi_cmd, 0, 6);
scsi_cmd[0] = INQUIRY;
scsi_cmd[4] = (unsigned char) try_inquiry_len;
......@@ -582,7 +584,7 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
inq_result, try_inquiry_len, &sshdr,
HZ / 2 + HZ * scsi_inq_timeout, 3,
NULL);
&resid);
SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s "
"with code 0x%x\n",
......@@ -603,6 +605,14 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
(sshdr.ascq == 0))
continue;
}
} else {
/*
* if nothing was transferred, we try
* again. It's a workaround for some USB
* devices.
*/
if (resid == try_inquiry_len)
continue;
}
break;
}
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment