[PATCH] libata: make ata_set_mode() handle no-device case properly
Make ata_set_mode() return without doing anything if there is no
device on the port. This is in preparation for ata_bus_probe()
changes.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index c10c550..913e378 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -1823,7 +1823,7 @@
*/
static void ata_set_mode(struct ata_port *ap)
{
- int i, rc, used_dma = 0;
+ int i, rc, used_dma = 0, found = 0;
/* step 1: calculate xfer_mask */
for (i = 0; i < ATA_MAX_DEVICES; i++) {
@@ -1842,9 +1842,12 @@
dev->pio_mode = ata_xfer_mask2mode(pio_mask);
dev->dma_mode = ata_xfer_mask2mode(dma_mask);
+ found = 1;
if (dev->dma_mode)
used_dma = 1;
}
+ if (!found)
+ return;
/* step 2: always set host PIO timings */
rc = ata_host_set_pio(ap);