Commit 9529a5ba authored Oct 25, 2005 by Lee Revell Committed by Jaroslav Kysela Nov 04, 2005

[ALSA] emu10k1 - Use 31 bit DMA mask for Audigy



Modules: EMU10K1/EMU10K2 driver

It appears that either the Audigy DMA engine or the Linux kernel cannot
handle 32 bit DMA with this device.  Problem manifests as noise when
using more than 2GB of RAM, possibly only on 64 bit machines.

The OSS driver actually uses a 29 bit DMA mask for both devices, this
seems like overkill for now.

Signed-off-by: Lee Revell <rlrevell@joe-job.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

parent d91c64c8

include/sound/emu10k1.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -48,7 +48,8 @@

		/* FIXME? - according to the OSS driver the EMU10K1 needs a 29 bit DMA mask */
		#define EMU10K1_DMA_MASK 0x7fffffffUL /* 31bit */
		#define AUDIGY_DMA_MASK 0xffffffffUL /* 32bit */
		#define AUDIGY_DMA_MASK 0x7fffffffUL /* 31bit FIXME - 32 should work? */
		/* See ALSA bug #1276 - rlrevell */

		#define TMEMSIZE 256*1024
		#define TMEMSIZEREG 4

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