cmd64x: don't clear the other channel's interrupt

Make sure to not clear the other IDE channel's interrupt when clearing an IDE
interrupt via the MRDMODE register.

Thanks to Bart for finding a coding mistake.

Bart:

This fixes regression from commit 66602c83dcb6a5d82772d88ae7a32cd4a1213528
("cmd64x: use interrupt status from MRDMODE register (take 2)").

Extra thanks to Martin for reporting and bisecting the issue.

From: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Tested-by: Martin Rogge <marogge@onlinehome.de>
Tested-by: Milan Kocian <milon@wq.cz>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/ide/pci/cmd64x.c b/drivers/ide/pci/cmd64x.c
index ea0143ef5fe5..51fca441c294 100644
--- a/drivers/ide/pci/cmd64x.c
+++ b/drivers/ide/pci/cmd64x.c
@@ -1,5 +1,5 @@
 /*
- * linux/drivers/ide/pci/cmd64x.c               Version 1.50    May 10, 2007
+ * linux/drivers/ide/pci/cmd64x.c               Version 1.51    Nov 8, 2007
  *
  * cmd64x.c: Enable interrupts at initialization time on Ultra/PCI machines.
  *           Due to massive hardware bugs, UltraDMA is only supported
@@ -339,7 +339,8 @@ static int cmd648_ide_dma_end (ide_drive_t *drive)
         u8  mrdmode             = inb(hwif->dma_master + 0x01);
 
         /* clear the interrupt bit */
-        outb(mrdmode | irq_mask, hwif->dma_master + 0x01);
+        outb((mrdmode & ~(MRDMODE_INTR_CH0 | MRDMODE_INTR_CH1)) | irq_mask,
+             hwif->dma_master + 0x01);
 
         return err;
 }