From: Takashi Iwai <tiwai@suse.de>
Date: Wed, 29 Jun 2016 13:23:08 +0000 (+0200)
Subject: ALSA: au88x0: Fix calculation in vortex_wtdma_bufshift()
X-Git-Tag: v3.2.82~18
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=a620c002d0a7c101f8e5790a6f57aa62209693f4

ALSA: au88x0: Fix calculation in vortex_wtdma_bufshift()

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: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/sound/pci/au88x0/au88x0_core.c b/sound/pci/au88x0/au88x0_core.c
index 489150380eac..dd6e74fd3d28 100644
--- a/sound/pci/au88x0/au88x0_core.c
+++ b/sound/pci/au88x0/au88x0_core.c
@@ -1444,9 +1444,8 @@ 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 {