[PATCH 4.6 169/203] ALSA: au88x0: Fix calculation in vortex_wtdma_bufshift()

Greg Kroah-Hartman
2016-07-25T21:42:16Z

From: Takashi Iwai <tiwai@suse.de>

commit 62db7152c924e4c060e42b34a69cd39658e8a0dc upstream.

vortex_wtdma_bufshift() function does calculate the page index
wrongly, first masking then shift, which always results in zero.
The proper computation is to first shift, then mask.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/pci/au88x0/au88x0_core.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

--- a/sound/pci/au88x0/au88x0_core.c
+++ b/sound/pci/au88x0/au88x0_core.c
@@ -1444,9 +1444,8 @@ static int vortex_wtdma_bufshift(vortex_
int page, p, pp, delta, i;

page =
- (hwread(vortex->mmio, VORTEX_WTDMA_STAT + (wtdma << 2)) &
- WT_SUBBUF_MASK)
- >> WT_SUBBUF_SHIFT;
+ (hwread(vortex->mmio, VORTEX_WTDMA_STAT + (wtdma << 2))
+ >> WT_SUBBUF_SHIFT) & WT_SUBBUF_MASK;
if (dma->nr_periods >= 4)
delta = (page - dma->period_real) & 3;
else {