[PATCH libata-dev-2.6] libata: flush COMRESET write

Brett Russ
2005-03-25T23:19:17Z

Jeff,

I'm seeing single drives getting stuck in ata_busy_sleep() with these
log messages on boot:

<4>ata2 is slow to respond, please be patient
<3>ata2 failed to respond (30 secs)

One thing I found was the bug fixed below, where the COMRESET wasn't
getting flushed properly. This may or may not be the reason, but it
can't hurt. I have to keep looking and testing.

I wanted to also send a separate patch to ensure the port was stopped
before issuing COMRESET, since this is required by at least the ICH6R,
but the port_stop() routines seemed too heavy to call from
__sata_phy_reset() so I'm not sending anything like that yet.

Signed-off-by: Brett Russ <russb@emc.com>

Index: libata-dev-2.6/drivers/scsi/libata-core.c
===================================================================
--- libata-dev-2.6.orig/drivers/scsi/libata-core.c 2005-03-23 16:44:48.000000000 -0500
+++ libata-dev-2.6/drivers/scsi/libata-core.c 2005-03-25 16:58:22.000000000 -0500
@@ -1262,7 +1262,7 @@

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 */
+ scr_read(ap, SCR_CONTROL); /* dummy read; flush */
udelay(400); /* FIXME: a guess */
}
scr_write(ap, SCR_CONTROL, 0x300); /* issue phy wake/clear reset */