[alsa-devel] [PATCH 1/1] ALSA: CA0132 - Ensure SCP packet is little-endian format

Ian Minett ian_minett at creativelabs.com
Thu Sep 27 03:23:59 CEST 2012

From: Ian Minett <ian_minett at creativelabs.com>

Hi Takashi,
Great - good to hear the previous DSP loader patches are now living in the 
hda-ca0132-dsp branch. This patch is based on that branch, and addresses 
the SCP packet endianness.

>> The firmware does need to be reloaded when the chip loses power, so it 
>> doesn't survive S3.
>OK, we need suspend/resume hooks, too.

Do we need to do anything specific to handle this? The firmware is already 
restored upon S3 by the current caching code.

- Ian


The DSP firmware expects the SCP data to be in little-endian
format regardless of the host architecture.

Signed-off-by: Ian Minett <ian_minett at creativelabs.com>

diff --git a/sound/pci/hda/patch_ca0132.c b/sound/pci/hda/patch_ca0132.c
index 2fd3121..4d7cda4 100644
--- a/sound/pci/hda/patch_ca0132.c
+++ b/sound/pci/hda/patch_ca0132.c
@@ -28,6 +28,7 @@
 #include <linux/mutex.h>
 #include <linux/module.h>
 #include <linux/firmware.h>
+#include <asm/unaligned.h>
 #include <sound/core.h>
 #include "hda_codec.h"
 #include "hda_local.h"
@@ -701,9 +702,13 @@ static int dspio_send(struct hda_codec *codec, unsigned int reg,
 	unsigned int res;
 	int retry = 50;
+	/* Handling for Big Endian machine */
+	unsigned int val;
+	put_unaligned_le32(data, &val);
 	/* send bits of data specified by reg to dsp */
 	do {
-		res = snd_hda_codec_read(codec, WIDGET_DSP_CTRL, 0, reg, data);
+		res = snd_hda_codec_read(codec, WIDGET_DSP_CTRL, 0, reg, val);
 		if ((res >= 0) && (res != VENDOR_STATUS_DSPIO_BUSY))
 			return res;
 	} while (--retry);

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