[patch 03/15] opti621: disable read prefetch

[Greg KH]

2.6.25-stable review patch.  If anyone has any objections, please let us
know.

------------------
From: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>

commit 62128b2ca812c1266f4ff7bac068bf0b626c6179 upstream

This fixes 2.6.25 regression (kernel.org bugzilla bug #10723) caused by:

commit 912fb29a36a7269ac1c4a4df45bc0ac1d2637972
Author: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>
Date:   Fri Oct 19 00:30:11 2007 +0200

    opti621: always tune PIO
...

Based on a bugreport from Juergen Kosel & inspired by pata_opti.c code.

Bisected-by: Juergen Kosel <juergen.kosel@xxxxxx>
Tested-by: Juergen Kosel <juergen.kosel@xxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/ide/pci/opti621.c |   15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

--- a/drivers/ide/pci/opti621.c
+++ b/drivers/ide/pci/opti621.c
@@ -103,18 +103,6 @@
  *  address: 50 ns, data: 50 ns, recovery: 100 ns.
  */
 
-/* #define READ_PREFETCH 0 */
-/* Uncomment for disable read prefetch.
- * There is some readprefetch capatibility in hdparm,
- * but when I type hdparm -P 1 /dev/hda, I got errors
- * and till reset drive is inaccessible.
- * This (hw) read prefetch is safe on my drive.
- */
-
-#ifndef READ_PREFETCH
-#define READ_PREFETCH 0x40 /* read prefetch is enabled */
-#endif /* else read prefetch is disabled */
-
 #define READ_REG 0	/* index of Read cycle timing register */
 #define WRITE_REG 1	/* index of Write cycle timing register */
 #define CNTRL_REG 3	/* index of Control register */
@@ -260,7 +248,8 @@ static void opti621_set_pio_mode(ide_dri
 
 	cycle1 = ((first.data_time-1)<<4)  | (first.recovery_time-2);
 	cycle2 = ((second.data_time-1)<<4) | (second.recovery_time-2);
-	misc = READ_PREFETCH | ((ax-1)<<4) | ((drdy-2)<<1);
+
+	misc = ((ax - 1) << 4) | ((drdy - 2) << 1);
 
 #ifdef OPTI621_DEBUG
 	printk("%s: master: address: %d, data: %d, "

-- 
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