libata: add 150ms between completion of hardreset and status checking

Follow the old SRST rule and delay 150ms between completion of
hardreset and status checking.  Debouncing delay should usually cover
this but debounce duration could be shorter than 150ms under certain
circumstances.

Usefulness depends on host controller implementation but it can't hurt
and serves as a reminder that 2s delay for GoVault should also be
added here.

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

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 5c2e581..6a2083a 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -3023,6 +3023,9 @@ int sata_std_hardreset(struct ata_port *ap, unsigned int *class)
                return 0;
        }
 
+       /* wait a while before checking status, see SRST for more info */
+       msleep(150);
+
        if (ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT)) {
                ata_port_printk(ap, KERN_ERR,
                                "COMRESET failed (device not ready)\n");