Enable read ahead and write cache enable if supported by

the disk rather than depending on the disk to have it on.

A bunch of people have suggested this should go in.

1 files changed, 14 insertions, 1 deletions

diff --git a/sys/dev/ata/wd.c b/sys/dev/ata/wd.c
index 45fb5a85aad..91910a54d28 100644
--- a/sys/dev/ata/wd.c
+++ b/sys/dev/ata/wd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: wd.c,v 1.66 2007/06/20 18:15:46 deraadt Exp $ */
+/*	$OpenBSD: wd.c,v 1.67 2007/11/26 23:59:01 jsg Exp $ */
 /*	$NetBSD: wd.c,v 1.193 1999/02/28 17:15:27 explorer Exp $ */
 
 /*
@@ -224,12 +224,16 @@ wdattach(struct device *parent, struct device *self, void *aux)
 	struct wd_softc *wd = (void *)self;
 	struct ata_atapi_attach *aa_link= aux;
 	struct wdc_command wdc_c;
+	struct channel_softc *chp;
 	int i, blank;
+	u_int8_t drive;
 	char buf[41], c, *p, *q;
 	WDCDEBUG_PRINT(("wdattach\n"), DEBUG_FUNCS | DEBUG_PROBE);
 
 	wd->openings = aa_link->aa_openings;
 	wd->drvp = aa_link->aa_drv_data;
+	chp = wd->drvp->chnl_softc;
+	drive = wd->drvp->drive;
 
 	strlcpy(wd->drvp->drive_name, wd->sc_dev.dv_xname,
 	    sizeof(wd->drvp->drive_name));
@@ -322,6 +326,15 @@ wdattach(struct device *parent, struct device *self, void *aux)
 	    self->dv_xname, wd->sc_params.atap_dmatiming_mimi,
 	    wd->sc_params.atap_dmatiming_recom), DEBUG_PROBE);
 
+	/* use read look ahead if supported */
+	if (wd->sc_params.atap_cmd_set1 & WDC_CMD1_AHEAD)
+		wdccommand(chp, drive, SET_FEATURES, 0, 0, 0, 0,
+		    WDSF_READAHEAD_EN);
+	/* use write cache if supported */
+	if (wd->sc_params.atap_cmd_set1 & WDC_CMD1_CACHE)
+		wdccommand(chp, drive, SET_FEATURES, 0, 0, 0, 0,
+		    WDSF_EN_WR_CACHE);
+
 	/*
 	 * FREEZE LOCK the drive so malicous users can't lock it on us.
 	 * As there is no harm in issuing this to drives that don't