PATCH: fix our handling of BIOS forced PIO serverworks OSB4

[Alan Cox]

(Robert Hentosh & me)
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux-2.5.67/drivers/ide/pci/serverworks.c linux-2.5.67-ac1/drivers/ide/pci/serverworks.c
--- linux-2.5.67/drivers/ide/pci/serverworks.c	2003-03-26 19:59:51.000000000 +0000
+++ linux-2.5.67-ac1/drivers/ide/pci/serverworks.c	2003-04-06 18:44:38.000000000 +0100
@@ -419,7 +419,13 @@
 
 static void svwks_tune_drive (ide_drive_t *drive, u8 pio)
 {
-	(void) svwks_tune_chipset(drive, (XFER_PIO_0 + pio));
+	/* Tune to desired value or to "best". We must not adjust
+	   "best" when we adjust from pio numbers to rate values! */
+	   
+	if(pio != 255)
+		(void) svwks_tune_chipset(drive, (XFER_PIO_0 + pio));
+	else
+		(void) svwks_tune_chipset(drive, 255);
 }
 
 static int config_chipset_for_dma (ide_drive_t *drive)