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authorBartlomiej Zolnierkiewicz <bzolnier@gmail.com>2010-01-18 07:20:21 +0000
committerDavid S. Miller <davem@davemloft.net>2010-01-19 01:42:00 -0800
commit68d0a036162f12d8be07c9fc140507cc1c8c6120 (patch)
treefef5c49741892eb0785dc71d7fd27bacd4ad61f8 /drivers
parenta354ae8747d0687093ce244e76b15b6174d2f098 (diff)
downloadlinux-68d0a036162f12d8be07c9fc140507cc1c8c6120.tar.gz
via82cxxx: fix UDMA settings programming
* preserve 80-wire cable detection bit
* don't clear UDMA settings when programming PIO/MWDMA modes

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/ide/via82cxxx.c19
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/ide/via82cxxx.c b/drivers/ide/via82cxxx.c
index 3db35b0142dc..fbecf8ea8207 100644
--- a/drivers/ide/via82cxxx.c
+++ b/drivers/ide/via82cxxx.c
@@ -146,10 +146,25 @@ static void via_set_speed(ide_hwif_t *hwif, u8 dn, struct ide_timing *timing)
 	case ATA_UDMA4: t = timing->udma ? (0xe8 | (clamp_val(timing->udma, 2, 9) - 2)) : 0x0f; break;
 	case ATA_UDMA5: t = timing->udma ? (0xe0 | (clamp_val(timing->udma, 2, 9) - 2)) : 0x07; break;
 	case ATA_UDMA6: t = timing->udma ? (0xe0 | (clamp_val(timing->udma, 2, 9) - 2)) : 0x07; break;
-	default: return;
 	}
 
-	pci_write_config_byte(dev, VIA_UDMA_TIMING + (3 - dn), t);
+	/* Set UDMA unless device is not UDMA capable */
+	if (vdev->via_config->udma_mask) {
+		u8 udma_etc;
+
+		pci_read_config_byte(dev, VIA_UDMA_TIMING + 3 - dn, &udma_etc);
+
+		/* clear transfer mode bit */
+		udma_etc &= ~0x20;
+
+		if (timing->udma) {
+			/* preserve 80-wire cable detection bit */
+			udma_etc &= 0x10;
+			udma_etc |= t;
+		}
+
+		pci_write_config_byte(dev, VIA_UDMA_TIMING + 3 - dn, udma_etc);
+	}
 }
 
 /**