ahci: fix notification handling
Asynchronous notification on ICH9 didn't work because it didn't write
AN FIS into the RX area - it only updates SNotification. Also,
snooping SDB_FIS RX area is racy against further SDB FIS receptions.
Let sata_async_notification() determine using SNTF if it's available
and snoop RX area iff SNTF isn't available
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 6633c742..abfb72a 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1420,6 +1420,7 @@
void __iomem *port_mmio = ap->ioaddr.cmd_addr;
struct ata_eh_info *ehi = &ap->link.eh_info;
struct ahci_port_priv *pp = ap->private_data;
+ struct ahci_host_priv *hpriv = ap->host->private_data;
u32 status, qc_active;
int rc, known_irq = 0;
@@ -1432,17 +1433,28 @@
}
if (status & PORT_IRQ_SDB_FIS) {
- /* If the 'N' bit in word 0 of the FIS is set, we just
- * received asynchronous notification. Tell libata
- * about it. Note that as the SDB FIS itself is
- * accessible, SNotification can be emulated by the
- * driver but don't bother for the time being.
+ /* If SNotification is available, leave notification
+ * handling to sata_async_notification(). If not,
+ * emulate it by snooping SDB FIS RX area.
+ *
+ * Snooping FIS RX area is probably cheaper than
+ * poking SNotification but some constrollers which
+ * implement SNotification, ICH9 for example, don't
+ * store AN SDB FIS into receive area.
*/
- const __le32 *f = pp->rx_fis + RX_FIS_SDB;
- u32 f0 = le32_to_cpu(f[0]);
-
- if (f0 & (1 << 15))
+ if (hpriv->cap & HOST_CAP_SNTF)
sata_async_notification(ap);
+ else {
+ /* If the 'N' bit in word 0 of the FIS is set,
+ * we just received asynchronous notification.
+ * Tell libata about it.
+ */
+ const __le32 *f = pp->rx_fis + RX_FIS_SDB;
+ u32 f0 = le32_to_cpu(f[0]);
+
+ if (f0 & (1 << 15))
+ sata_async_notification(ap);
+ }
}
/* pp->active_link is valid iff any command is in flight */