[libata sata_sil] cleaner, better version of errata workarounds

No longer unfairly punishes non-errata Seagate and Maxtor drives.

drivers/scsi/sata_sil.c

@@ -64,6 +64,9 @@ enum {
 	SIL_IDE3_CTL		= 0x2CA,
 	SIL_IDE3_BMDMA		= 0x208,
 	SIL_IDE3_SCR		= 0x380,
+
+	SIL_QUIRK_MOD15WRITE	= (1 << 0),
+	SIL_QUIRK_UDMA5MAX	= (1 << 1),
 };
 
 static void sil_set_piomode (struct ata_port *ap, struct ata_device *adev,
@@ -82,6 +85,27 @@ static struct pci_device_id sil_pci_tbl[] = {
 	{ }	/* terminate list */
 };
 
+
+/* TODO firmware versions should be added - eric */
+struct sil_drivelist {
+	const char * product;
+	unsigned int quirk;
+} sil_blacklist [] = {
+	{ "ST320012AS",		SIL_QUIRK_MOD15WRITE },
+	{ "ST330013AS",		SIL_QUIRK_MOD15WRITE },
+	{ "ST340017AS",		SIL_QUIRK_MOD15WRITE },
+	{ "ST360015AS",		SIL_QUIRK_MOD15WRITE },
+	{ "ST380023AS",		SIL_QUIRK_MOD15WRITE },
+	{ "ST3120023AS",	SIL_QUIRK_MOD15WRITE },
+	{ "ST340014ASL",	SIL_QUIRK_MOD15WRITE },
+	{ "ST360014ASL",	SIL_QUIRK_MOD15WRITE },
+	{ "ST380011ASL",	SIL_QUIRK_MOD15WRITE },
+	{ "ST3120022ASL",	SIL_QUIRK_MOD15WRITE },
+	{ "ST3160021ASL",	SIL_QUIRK_MOD15WRITE },
+	{ "Maxtor 4D060H3",	SIL_QUIRK_UDMA5MAX },
+	{ }
+};
+
 static struct pci_driver sil_pci_driver = {
 	.name			= DRV_NAME,
 	.id_table		= sil_pci_tbl,
@@ -207,34 +231,52 @@ static void sil_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val)
  *	information on these errata, I will create a more exhaustive
  *	list, and apply the fixups to only the specific
  *	devices/hosts/firmwares that need it.
+ *
+ *	20040111 - Seagate drives affected by the Mod15Write bug are blacklisted
+ *	The Maxtor quirk is in the blacklist, but I'm keeping the original
+ *	pessimistic fix for the following reasons:
+ *	- There seems to be less info on it, only one device gleaned off the
+ *	Windows	driver, maybe only one is affected.  More info would be greatly
+ *	appreciated.
+ *	- But then again UDMA5 is hardly anything to complain about
  */
 static void sil_dev_config(struct ata_port *ap, struct ata_device *dev)
 {
+	unsigned int n, quirks = 0;
+	u32 class_rev = 0;
 	const char *s = &dev->product[0];
 	unsigned int len = strnlen(s, sizeof(dev->product));
 
+	pci_read_config_dword(ap->host_set->pdev, PCI_CLASS_REVISION, &class_rev);
+	class_rev &= 0xff;
+
 	/* ATAPI specifies that empty space is blank-filled; remove blanks */
 	while ((len > 0) && (s[len - 1] == ' '))
 		len--;
 
-	/* limit to udma5 */
-	if (!memcmp(s, "Maxtor ", 7)) {
-		printk(KERN_INFO "ata%u(%u): applying pessimistic Maxtor errata fix\n",
-		       ap->id, dev->devno);
-		ap->udma_mask &= ATA_UDMA5;
-		return;
+	for (n = 0; sil_blacklist[n].product; n++) 
+		if (!memcmp(sil_blacklist[n].product, s,
+			    strlen(sil_blacklist[n].product))) {
+			quirks = sil_blacklist[n].quirk;
+			break;
 		}
 	
 	/* limit requests to 15 sectors */
-	if ((len > 4) && (!memcmp(s, "ST", 2))) {
-		if ((!memcmp(s + len - 2, "AS", 2)) ||
-		    (!memcmp(s + len - 3, "ASL", 3))) {
-			printk(KERN_INFO "ata%u(%u): applying pessimistic Seagate errata fix\n",
+	if ((class_rev <= 0x01) && (quirks & SIL_QUIRK_MOD15WRITE)) {
+		printk(KERN_INFO "ata%u(%u): applying Seagate errata fix\n",
 		       ap->id, dev->devno);
 		ap->host->max_sectors = 15;
 		ap->host->hostt->max_sectors = 15;
 		return;
 	}
+
+	/* limit to udma5 */
+	/* is this for (class_rev <= 0x01) only, too? */
+	if (quirks & SIL_QUIRK_UDMA5MAX) {
+		printk(KERN_INFO "ata%u(%u): applying Maxtor errata fix %s\n",
+		       ap->id, dev->devno, s);
+		ap->udma_mask &= ATA_UDMA5;
+		return;
 	}
 }