[PATCH 3.12 023/100] ALSA: au88x0: Fix calculation in vortex_wtdma_bufshift()

[Jiri Slaby]

From: Takashi Iwai <tiwai@xxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

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@xxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 sound/pci/au88x0/au88x0_core.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/sound/pci/au88x0/au88x0_core.c b/sound/pci/au88x0/au88x0_core.c
index ae59dbaa53d9..42d4b13f1fa7 100644
--- a/sound/pci/au88x0/au88x0_core.c
+++ b/sound/pci/au88x0/au88x0_core.c
@@ -1442,9 +1442,8 @@ static int vortex_wtdma_bufshift(vortex_t * vortex, int wtdma)
 	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 {
-- 
2.9.3