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authorTejun Heo <htejun@gmail.com>2007-10-09 15:02:23 +0900
committerJeff Garzik <jeff@garzik.org>2007-10-12 14:55:47 -0400
commit5f226c6bf78edab023ed1ea679531731d9df92a6 (patch)
tree01e0dff1224476aa52c240ee958ec7948bb85cc6 /drivers/ata
parent1c954a4d9a9e351fa3509533fd8dd5f3821206cd (diff)
downloadlwn-5f226c6bf78edab023ed1ea679531731d9df92a6.tar.gz
lwn-5f226c6bf78edab023ed1ea679531731d9df92a6.zip
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>
Diffstat (limited to 'drivers/ata')
-rw-r--r--drivers/ata/ahci.c30
1 files changed, 21 insertions, 9 deletions
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 6633c7422fc4..abfb72aae3de 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1420,6 +1420,7 @@ static void ahci_port_intr(struct ata_port *ap)
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 @@ static void ahci_port_intr(struct ata_port *ap)
}
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 */