[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 f712e4cfd9dcb7eb1dafba2dc59f7e1c584f80f2..7cf3eb02352140d8f8558533aee4107c8fd1a445 100644 (file)
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -776,7 +776,7 @@ static void update_ordered(ide_drive_t *drive)
                 * 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 05fbd9298db7c7cd5e265a8d9a65a994ec1c81f5..defd4b4bd37488ab38198e8ab86f963c438e2809 100644 (file)
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -1539,7 +1539,7 @@ static int __init ide_setup(char *s)
                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 @@ static int __init ide_setup(char *s)
                        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 dc7abef1096545c167e9ee7122ddc32b5712413b..99620451d958730a7754cf80acf572a770d75e40 100644 (file)
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -571,6 +571,7 @@ typedef struct ide_drive_s {
        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 */