[SCSI] retry with missing data for INQUIRY (5cd3bbfa) · Commits · 戴 / test

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:

FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by:

James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/scsi_scan.c

+11 −1

Original line number	Diff line number	Diff line
		@@ -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;
		}

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