From 74f7c840cad3e1dff186088b4fb148193beea69c Mon Sep 17 00:00:00 2001
From: Mark Kettenis <kettenis@cvs.openbsd.org>
Date: Tue, 29 Dec 2015 09:44:47 +0000
Subject: Set UltraDMA transfer mode.  Some (early?) SATA drives, such as the
 Maxtor 7Y250M0, refuse to do DMA unless the transfer mode has been set.  This
 causes reads (and presumably writes) to time out.

Unlike the wdc code, this only sets the UltraDMA transfer mode.  If we ever
want to support ancient PATA drivers through the atascsi layer, we probably
need to set the PIO and/or MWDMA transfer modes as well.

ok jmatthew@, dlg@)
---
 sys/dev/ata/atascsi.c | 22 +++++++++++++++++++++-
 sys/dev/ata/atascsi.h |  5 ++++-
 2 files changed, 25 insertions(+), 2 deletions(-)

(limited to 'sys/dev/ata')

diff --git a/sys/dev/ata/atascsi.c b/sys/dev/ata/atascsi.c
index bb825a90420..c4c67ffd3f3 100644
--- a/sys/dev/ata/atascsi.c
+++ b/sys/dev/ata/atascsi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: atascsi.c,v 1.125 2015/08/28 00:03:53 deraadt Exp $ */
+/*	$OpenBSD: atascsi.c,v 1.126 2015/12/29 09:44:46 kettenis Exp $ */
 
 /*
  * Copyright (c) 2007 David Gwynne <dlg@openbsd.org>
@@ -266,6 +266,8 @@ atascsi_probe(struct scsi_link *link)
 	int				port, type, qdepth;
 	int				rv;
 	u_int16_t			cmdset;
+	u_int16_t			validinfo, ultradma;
+	int				i, xfermode = -1;
 
 	port = link->target;
 	if (port >= as->as_link.adapter_buswidth)
@@ -364,6 +366,24 @@ atascsi_probe(struct scsi_link *link)
 	if (type != ATA_PORT_T_DISK)
 		return (0);
 
+	/*
+	 * Early SATA drivers (as well as PATA drives) need to have
+	 * their transfer mode set properly, otherwise commands that
+	 * use DMA will time out.
+	 */
+	validinfo = letoh16(ap->ap_identify.validinfo);
+	if (ISSET(validinfo, ATA_ID_VALIDINFO_ULTRADMA)) {
+		ultradma = letoh16(ap->ap_identify.ultradma);
+		for (i = 7; i >= 0; i--) {
+			if (ultradma & (1 << i)) {
+				xfermode = ATA_SF_XFERMODE_UDMA | i;
+				break;
+			}
+		}
+	}
+	if (xfermode != -1)
+		(void)atascsi_port_set_features(ap, ATA_SF_XFERMODE, xfermode);
+
 	if (as->as_capability & ASAA_CAP_NCQ &&
 	    ISSET(letoh16(ap->ap_identify.satacap), ATA_SATACAP_NCQ) &&
 	    (link->lun == 0 || as->as_capability & ASAA_CAP_PMP_NCQ)) {
diff --git a/sys/dev/ata/atascsi.h b/sys/dev/ata/atascsi.h
index ce15b954dc2..93e3021c8fd 100644
--- a/sys/dev/ata/atascsi.h
+++ b/sys/dev/ata/atascsi.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: atascsi.h,v 1.49 2015/05/15 10:54:26 dlg Exp $ */
+/*	$OpenBSD: atascsi.h,v 1.50 2015/12/29 09:44:46 kettenis Exp $ */
 
 /*
  * Copyright (c) 2007 David Gwynne <dlg@openbsd.org>
@@ -53,6 +53,8 @@ struct scsi_link;
  * ATA SET FEATURES subcommands
  */
 #define ATA_SF_WRITECACHE_EN	0x02
+#define ATA_SF_XFERMODE		0x03
+#define  ATA_SF_XFERMODE_UDMA	0x40
 #define ATA_SF_LOOKAHEAD_EN	0xaa
 
 struct ata_identify {
@@ -77,6 +79,7 @@ struct ata_identify {
 	u_int16_t	piomode;	/*  51 */
 	u_int16_t	dmamode;	/*  52 */
 	u_int16_t	validinfo;	/*  53 */
+#define ATA_ID_VALIDINFO_ULTRADMA	0x0004
 	u_int16_t	curcyls;	/*  54 */
 	u_int16_t	curheads;	/*  55 */
 	u_int16_t	cursectrk;	/*  56 */
-- 
cgit v1.2.3