libata: mask off DET when restoring SControl for detach

htejun · Jeff Garzik · commit 299246f9a2a4 · 2008-11-04T01:08:33.000-05:00
libata restores SControl on detach; however, trying to restore
non-zero DET can cause undeterministic behavior including PMP device
going offline till power cycling.  Mask off DET when restoring
SControl.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Jeff Garzik &lt;jgarzik@redhat.com&gt;
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
@@ -5936,7 +5936,7 @@ static void ata_port_detach(struct ata_port *ap)
 	 * to us.  Restore SControl and disable all existing devices.
 	 */
 	__ata_port_for_each_link(link, ap) {
-		sata_scr_write(link, SCR_CONTROL, link->saved_scontrol);
+		sata_scr_write(link, SCR_CONTROL, link->saved_scontrol & 0xff0);
 		ata_link_for_each_dev(dev, link)
 			ata_dev_disable(dev);
 	}

Original file line number	Diff line number	Diff line change
`@@ -5936,7 +5936,7 @@ static void ata_port_detach(struct ata_port *ap)`
`5936`	`5936`	`* to us. Restore SControl and disable all existing devices.`
`5937`	`5937`	`*/`
`5938`	`5938`	`__ata_port_for_each_link(link, ap) {`
`5939`		`- sata_scr_write(link, SCR_CONTROL, link->saved_scontrol);`
	`5939`	`+ sata_scr_write(link, SCR_CONTROL, link->saved_scontrol & 0xff0);`
`5940`	`5940`	`ata_link_for_each_dev(dev, link)`
`5941`	`5941`	`ata_dev_disable(dev);`
`5942`	`5942`	`}`