From: Brett Russ <russb@emc.com>
Updated patch to fix erroneous flush of COMRESET set and missing flush of
COMRESET clear. Created a new routine scr_write_flush() to try to prevent
this in the future. Also, this patch is based on libata-2.6 instead of the
previous libata-dev-2.6 based patch.
Signed-off-by: Brett Russ <russb@emc.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/drivers/scsi/libata-core.c | 6 +++---
25-akpm/include/linux/libata.h | 7 +++++++
2 files changed, 10 insertions(+), 3 deletions(-)
diff -puN drivers/scsi/libata-core.c~libata-flush-comreset-set-and-clear drivers/scsi/libata-core.c
--- 25/drivers/scsi/libata-core.c~libata-flush-comreset-set-and-clear 2005-03-28 16:07:30.000000000 -0800
+++ 25-akpm/drivers/scsi/libata-core.c 2005-03-28 16:07:30.000000000 -0800
@@ -1253,11 +1253,11 @@ void __sata_phy_reset(struct ata_port *a
unsigned long timeout = jiffies + (HZ * 5);
if (ap->flags & ATA_FLAG_SATA_RESET) {
- scr_write(ap, SCR_CONTROL, 0x301); /* issue phy wake/reset */
- scr_read(ap, SCR_STATUS); /* dummy read; flush */
+ /* issue phy wake/reset */
+ scr_write_flush(ap, SCR_CONTROL, 0x301);
udelay(400); /* FIXME: a guess */
}
- scr_write(ap, SCR_CONTROL, 0x300); /* issue phy wake/clear reset */
+ scr_write_flush(ap, SCR_CONTROL, 0x300); /* phy wake/clear reset */
/* wait for phy to become ready, if necessary */
do {
diff -puN include/linux/libata.h~libata-flush-comreset-set-and-clear include/linux/libata.h
--- 25/include/linux/libata.h~libata-flush-comreset-set-and-clear 2005-03-28 16:07:30.000000000 -0800
+++ 25-akpm/include/linux/libata.h 2005-03-28 16:07:30.000000000 -0800
@@ -584,6 +584,13 @@ static inline void scr_write(struct ata_
ap->ops->scr_write(ap, reg, val);
}
+static inline void scr_write_flush(struct ata_port *ap, unsigned int reg,
+ u32 val)
+{
+ ap->ops->scr_write(ap, reg, val);
+ (void) ap->ops->scr_read(ap, reg);
+}
+
static inline unsigned int sata_dev_present(struct ata_port *ap)
{
return ((scr_read(ap, SCR_STATUS) & 0xf) == 0x3) ? 1 : 0;
_