libata: ignore recovered PHY errors

No reason to get overzealous about recovered comm and data errors.
Some PHYs habitually sets them w/o no good reason and being draconian
about these soft error conditions doesn't seem to help anybody.

If need ever rises, we might need to add soft PHY error condition, say
AC_ERR_MAYBE_ATA_BUS and use it only to determine whether speed down
is necessary but I don't think that's very likely to happen.  It's far
more likely we'll get timeouts or fatal transmission errors if
recovered errors are so prominent that they hamper operation.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/libata-eh.c

@@ -1308,12 +1308,7 @@ static void ata_eh_analyze_serror(struct ata_link *link)
 	unsigned int err_mask = 0, action = 0;
 	u32 hotplug_mask;
 
-	if (serror & SERR_PERSISTENT) {
-		err_mask |= AC_ERR_ATA_BUS;
-		action |= ATA_EH_RESET;
-	}
-	if (serror &
-	    (SERR_DATA_RECOVERED | SERR_COMM_RECOVERED | SERR_DATA)) {
+	if (serror & (SERR_PERSISTENT | SERR_DATA)) {
 		err_mask |= AC_ERR_ATA_BUS;
 		action |= ATA_EH_RESET;
 	}