ide-cd: fix 'ireason' reporting in cdrom_pc_intr()

Mask 'ireason' variable so only the valid interrupt reason bits
will be reported on "drive appears confused" error.

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

diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 522580f29ddcfc67860dfccc0201071f6cbe5793..c7d77f0ad892d5ae82a1968e64d13b3374164dbd 100644 (file)
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1446,7 +1446,7 @@ static ide_startstop_t cdrom_pc_intr (ide_drive_t *drive)
                return ide_stopped;
 
        /* Read the interrupt reason and the transfer length. */
-       ireason = HWIF(drive)->INB(IDE_IREASON_REG);
+       ireason = HWIF(drive)->INB(IDE_IREASON_REG) & 0x3;
        lowcyl  = HWIF(drive)->INB(IDE_BCOUNTL_REG);
        highcyl = HWIF(drive)->INB(IDE_BCOUNTH_REG);
 
@@ -1487,7 +1487,7 @@ static ide_startstop_t cdrom_pc_intr (ide_drive_t *drive)
        if (thislen > len) thislen = len;
 
        /* The drive wants to be written to. */
-       if ((ireason & 3) == 0) {
+       if (ireason == 0) {
                if (!rq->data) {
                        blk_dump_rq_flags(rq, "cdrom_pc_intr, write");
                        goto confused;
@@ -1509,7 +1509,7 @@ static ide_startstop_t cdrom_pc_intr (ide_drive_t *drive)
        }
 
        /* Same drill for reading. */
-       else if ((ireason & 3) == 2) {
+       else if (ireason == 2) {
                if (!rq->data) {
                        blk_dump_rq_flags(rq, "cdrom_pc_intr, read");
                        goto confused;