RESEND: libata: check cdb len per dev instead of per host

Resending, with s/printk/DPRINTK/ as pointed out by Alan.

Fix libata to perform CDB len validation per device rather than per host. This way, validation still works when we have a mix of 12-byte and 16-byte devices on a common host interface.

---

diff -u --recursive --new-file --exclude-from=old/Documentation/dontdiff old/drivers/ata/libata-core.c new/drivers/ata/libata-core.c
@@ -1573,20 +1573,6 @@

		snprintf(desc, desc_sz, "NCQ (depth %d/%d)", hdepth, ddepth);
}

-static void ata_set_port_max_cmd_len(struct ata_port *ap) -{
- int i;
-
- if (ap->scsi_host) {
- unsigned int len = 0;
-
- for (i = 0; i < ATA_MAX_DEVICES; i++)
- len = max(len, ap->device[i].cdb_len);
-
- ap->scsi_host->max_cmd_len = len;
- }
-}
-
/**
* ata_dev_configure - Configure the specified ATA/ATAPI device
* @dev: Target device to configure
@@ -1767,8 +1753,6 @@

		}
	}

- ata_set_port_max_cmd_len(ap);
-

	/* limit bridge transfers to udma5, 200 sectors */
	if (ata_dev_knobble(dev)) {
		if (ata_msg_drv(ap) && print_info)
@@ -5675,7 +5659,7 @@
	shost->max_id = 16;
	shost->max_lun = 1;
	shost->max_channel = 1;

- shost->max_cmd_len = 12;
+ shost->max_cmd_len = 16;
}

/**

diff -u --recursive --new-file --exclude-from=old/Documentation/dontdiff old/drivers/ata/libata-scsi.c new/drivers/ata/libata-scsi.c
@@ -2748,8 +2748,9 @@

{
	int rc = 0;

- if (unlikely(!scmd->cmd_len)) {
- ata_dev_printk(dev, KERN_WARNING, "WARNING: zero len CDB\n");
+ if (unlikely(!scmd->cmd_len || scmd->cmd_len > dev->cdb_len)) {
+ DPRINTK("bad CDB len=%u, max=%u\n",

+			scmd->cmd_len, dev->cdb_len);
		scmd->result = DID_ERROR << 16;
		done(scmd);
		return 0;

applied, though I am disappointed that we had to add this check (as well as another one in an unrelated Tejun patch) to the fast path