ide: fix ->io_32bit race in set_io_32bit()

set_io_32bit() (ide_procset_t function) can race against running
PIO transfers.  Fix it by using ide_spin_wait_hwgroup().

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index 85740ae5d689..54943da6e4e5 100644
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -800,11 +800,17 @@ int set_io_32bit(ide_drive_t *drive, int arg)
         if (arg < 0 || arg > 1 + (SUPPORT_VLB_SYNC << 1))
                 return -EINVAL;
 
+        if (ide_spin_wait_hwgroup(drive))
+                return -EBUSY;
+
         drive->io_32bit = arg;
 #ifdef CONFIG_BLK_DEV_DTC2278
         if (HWIF(drive)->chipset == ide_dtc2278)
                 HWIF(drive)->drives[!drive->select.b.unit].io_32bit = arg;
 #endif /* CONFIG_BLK_DEV_DTC2278 */
+
+        spin_unlock_irq(&ide_lock);
+
         return 0;
 }