libata: clear link->eh_info.serror from ata_std_postreset()

link->eh_info.serror is used to cache SError for controllers which
need it cleared from interrupt handler to clear IRQ.  It also should
be cleared after reset just like SError itself.

Make ata_std_postreset() clear link->eh_info.serror too and update
sata_sil such that it doesn't care about bookkeeping the value.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/ata/libata-core.c

@@ -3923,6 +3923,7 @@ void ata_std_postreset(struct ata_link *link, unsigned int *classes)
 	/* clear SError */
 	if (sata_scr_read(link, SCR_ERROR, &serror) == 0)
 		sata_scr_write(link, SCR_ERROR, serror);
+	link->eh_info.serror = 0;
 
 	/* is double-select really necessary? */
 	if (classes[0] != ATA_DEV_NONE)

drivers/ata/sata_sil.c

@@ -394,16 +394,7 @@ static void sil_host_intr(struct ata_port *ap, u32 bmdma2)
 		 * it's PHYRDY CHG.
 		 */
 		if (serror & SERR_PHYRDY_CHG) {
-			/* Trigger hotplug and accumulate SError only
-			 * if the port isn't already frozen.
-			 * Otherwise, PHY events during hardreset
-			 * makes controllers with broken SIEN repeat
-			 * probing needlessly.
-			 */
-			if (!(ap->pflags & ATA_PFLAG_FROZEN)) {
-				ata_ehi_hotplugged(&ap->link.eh_info);
 			ap->link.eh_info.serror |= serror;
-			}
 			goto freeze;
 		}