[PATCH] ide: Allow IDE interface to specify its not capable of 32-bit operations

In some embedded systems the IDE hardware interface may only support 16-bit
or smaller accesses.  Allow the interface to specify if this is the case
and don't allow the drive or user to override the setting.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 10 insertions, 2 deletions

diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index e238b7da824b..ccf528d733bf 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -978,8 +978,6 @@ static void idedisk_setup (ide_drive_t *drive)
                 ide_dma_verbose(drive);
         printk("\n");
 
-        drive->no_io_32bit = id->dword_io ? 1 : 0;
-
         /* write cache enabled? */
         if ((id->csfo & 1) || (id->cfs_enable_1 & (1 << 5)))
                 drive->wcache = 1;
diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index 427d1c204174..1b7b4c531bc2 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -858,6 +858,15 @@ static void probe_hwif(ide_hwif_t *hwif)
                         }
                 }
         }
+
+        for (unit = 0; unit < MAX_DRIVES; ++unit) {
+                ide_drive_t *drive = &hwif->drives[unit];
+
+                if (hwif->no_io_32bit)
+                        drive->no_io_32bit = 1;
+                else
+                        drive->no_io_32bit = drive->id->dword_io ? 1 : 0;
+        }
 }
 
 static int hwif_init(ide_hwif_t *hwif);
diff --git a/include/linux/ide.h b/include/linux/ide.h
index a7fc4cc79b23..8d2db412ba9c 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -792,6 +792,7 @@ typedef struct hwif_s {
         unsigned        no_dsc     : 1; /* 0 default, 1 dsc_overlap disabled */
         unsigned        auto_poll  : 1; /* supports nop auto-poll */
         unsigned        sg_mapped  : 1; /* sg_table and sg_nents are ready */
+        unsigned        no_io_32bit : 1; /* 1 = can not do 32-bit IO ops */
 
         struct device   gendev;
         struct completion gendev_rel_comp; /* To deal with device release() */