[PATCH] ide: option to disable cache flushes for buggy drives
Some drives claim they support cache flushing, but get seriously
confused if you try. Add this option to be able to boot with
barriers enabled by default.
Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index f712e4c..7cf3eb0 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -776,7 +776,7 @@
* not available so we don't need to recheck that.
*/
capacity = idedisk_capacity(drive);
- barrier = ide_id_has_flush_cache(id) &&
+ barrier = ide_id_has_flush_cache(id) && !drive->noflush &&
(drive->addressing == 0 || capacity <= (1ULL << 28) ||
ide_id_has_flush_cache_ext(id));
diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index 05fbd92..defd4b4 100644
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -1539,7 +1539,7 @@
const char *hd_words[] = {
"none", "noprobe", "nowerr", "cdrom", "serialize",
"autotune", "noautotune", "minus8", "swapdata", "bswap",
- "minus11", "remap", "remap63", "scsi", NULL };
+ "noflush", "remap", "remap63", "scsi", NULL };
unit = s[2] - 'a';
hw = unit / MAX_DRIVES;
unit = unit % MAX_DRIVES;
@@ -1578,6 +1578,9 @@
case -10: /* "bswap" */
drive->bswap = 1;
goto done;
+ case -11: /* noflush */
+ drive->noflush = 1;
+ goto done;
case -12: /* "remap" */
drive->remap_0_to_1 = 1;
goto done;
diff --git a/include/linux/ide.h b/include/linux/ide.h
index dc7abef..9962045 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -571,6 +571,7 @@
u8 waiting_for_dma; /* dma currently in progress */
u8 unmask; /* okay to unmask other irqs */
u8 bswap; /* byte swap data */
+ u8 noflush; /* don't attempt flushes */
u8 dsc_overlap; /* DSC overlap */
u8 nice1; /* give potential excess bandwidth */
