[PATCH] sata_sil24: exit early from softreset if SStatus reports no device

sata_sil24 softreset routine used to check sata_dev_present() after
SRST is complete in the hope that SRST may do some good even when
SStatus reports no device.  This is okay as long as SRST timeout is
short (> 100ms in the current code) but it seems that not all SATA
devices are happy with short SRST timeout.

This patch makes softreset exit early without performing actual SRST
if SStatus reports no device in preparation for lengthening SRST
timeout.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/scsi/sata_sil24.c b/drivers/scsi/sata_sil24.c
index 8fb62427be84ec43f55813e2288b6f835011e7de..fa1a5ac606393b646e23059535a7ef66440dd88e 100644 (file)
--- a/drivers/scsi/sata_sil24.c
+++ b/drivers/scsi/sata_sil24.c
@@ -440,6 +440,12 @@ static int sil24_softreset(struct ata_port *ap, int verbose,
 
        DPRINTK("ENTER\n");
 
+       if (!sata_dev_present(ap)) {
+               DPRINTK("PHY reports no device\n");
+               *class = ATA_DEV_NONE;
+               goto out;
+       }
+
        /* temporarily turn off IRQs during SRST */
        irq_enable = readl(port + PORT_IRQ_ENABLE_SET);
        writel(irq_enable, port + PORT_IRQ_ENABLE_CLR);
@@ -469,18 +475,18 @@ static int sil24_softreset(struct ata_port *ap, int verbose,
        /* restore IRQs */
        writel(irq_enable, port + PORT_IRQ_ENABLE_SET);
 
-       if (sata_dev_present(ap)) {
-               if (!(irq_stat & PORT_IRQ_COMPLETE)) {
-                       DPRINTK("EXIT, srst failed\n");
-                       return -EIO;
-               }
-
-               sil24_update_tf(ap);
-               *class = ata_dev_classify(&pp->tf);
+       if (!(irq_stat & PORT_IRQ_COMPLETE)) {
+               DPRINTK("EXIT, srst failed\n");
+               return -EIO;
        }
+
+       sil24_update_tf(ap);
+       *class = ata_dev_classify(&pp->tf);
+
        if (*class == ATA_DEV_UNKNOWN)
                *class = ATA_DEV_NONE;
 
+ out:
        DPRINTK("EXIT, class=%u\n", *class);
        return 0;
 }