Commit 0e7d8d48 authored by Jan Evert van Grootheest's avatar Jan Evert van Grootheest Committed by Bartlomiej Zolnierkiewicz

ht6560b: force prefetch for some devices

Prefetch needs to be set for some ide devices to work when connected to
a ht6560b interface. This was not always done properly, causing a system
with a HD and CD on the primary interface to not work properly. Or, in
effect, hang hard.

This patch forces prefetch on devices before checking whether it
is necessary to change the settings in the interface

This patch should also be applied to 2.4. I don't currently have a
2.4 tree around.

(also change my email address)
Signed-off-by: default avatarJan Evert van Grootheest <>
Cc: Sergei Shtylyov <>
Cc: Alan Cox <>
Signed-off-by: default avatarBartlomiej Zolnierkiewicz <>
parent 1a1990f5
......@@ -21,18 +21,21 @@
* "Prefetch" mode bit OFF for ide disks and
* ON for anything else.
* Version 0.08 Need to force prefetch for CDs and other non-disk
* devices. (not sure which devices exactly need
* prefetch)
* HT-6560B EIDE-controller support
* To activate controller support use kernel parameter "ide0=ht6560b".
* Use hdparm utility to enable PIO mode support.
* Author: Mikko Ala-Fossi <>
* Jan Evert van Grootheest <>
* Jan Evert van Grootheest <>
* Try:
#define HT6560B_VERSION "v0.07"
#define HT6560B_VERSION "v0.08"
#include <linux/module.h>
#include <linux/types.h>
......@@ -130,15 +133,20 @@ static void ht6560b_selectproc (ide_drive_t *drive)
u8 select, timing;
select = HT_CONFIG(drive);
timing = HT_TIMING(drive);
* Need to enforce prefetch sometimes because otherwise
* it'll hang (hard).
if (drive->media != ide_disk || !drive->present)
if (select != current_select || timing != current_timing) {
current_select = select;
current_timing = timing;
if (drive->media != ide_disk || !drive->present)
......@@ -188,11 +196,12 @@ static int __init try_to_init_ht6560b(void)
(void) inb(0x1f7); /* IDE_STATUS_REG */
printk("\nht6560b " HT6560B_VERSION
printk("ht6560b " HT6560B_VERSION
": chipset detected and initialized"
#ifdef DEBUG
" with debug enabled"
return 1;
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