[alsa-devel] [PATCH 1/1] ALSA: CA0132 - Handle endianness of SCP buffer data

[Takashi Iwai]

At Tue, 27 Nov 2012 19:04:47 -0800,
Ian Minett wrote:
> 
> From: Ian Minett <ian_minett at creativelabs.com>
> 
> Handle endianness of the SCP buffer being sent to or from the
> DSP chip on big-endian host architectures.
> The SCP buffer is prepared in dspio_scp(), and bytes are swapped 
> before being transferred by the codec in dspio_send().
> Based on branch origin/topic/hda-ca0132-dsp.
> 
> We would appreciate any feedback you may have.

It's more straightforward to use cpu_to_le32() and le32_to_cpu()
than unaligned access.

Could you resend the patch with this rewrite?


thanks,

Takashi

> Thanks very much,
> - Ian
> 
> 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..8386a11 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"
> @@ -701,11 +702,16 @@ 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);
> -		if ((res >= 0) && (res != VENDOR_STATUS_DSPIO_BUSY))
> -			return res;
> +		res = snd_hda_codec_read(codec, WIDGET_DSP_CTRL, 0, reg, val);
> +		put_unaligned_le32(res, &val);
> +		if ((val >= 0) && (val != VENDOR_STATUS_DSPIO_BUSY))
> +			return val;
>  	} while (--retry);
>  
>  	return -EIO;
> @@ -719,11 +725,15 @@ static void dspio_write_wait(struct hda_codec *codec)
>  	int status;
>  	unsigned long timeout = jiffies + msecs_to_jiffies(1000);
>  
> +	/* Handling for Big Endian machine */
> +	unsigned int val;
> +
>  	do {
>  		status = snd_hda_codec_read(codec, WIDGET_DSP_CTRL, 0,
>  						VENDOR_DSPIO_STATUS, 0);
> -		if ((status == VENDOR_STATUS_DSPIO_OK) ||
> -		    (status == VENDOR_STATUS_DSPIO_SCP_RESPONSE_QUEUE_EMPTY))
> +		put_unaligned_le32(status, &val);
> +		if ((val == VENDOR_STATUS_DSPIO_OK) ||
> +		    (val == VENDOR_STATUS_DSPIO_SCP_RESPONSE_QUEUE_EMPTY))
>  			break;
>  		msleep(1);
>  	} while (time_before(jiffies, timeout));
> @@ -736,6 +746,8 @@ static int dspio_write(struct hda_codec *codec, unsigned int scp_data)
>  {
>  	struct ca0132_spec *spec = codec->spec;
>  	int status;
> +	/* Handling for Big Endian machine */
> +	unsigned int val = 0;
>  
>  	dspio_write_wait(codec);
>  
> @@ -751,8 +763,10 @@ static int dspio_write(struct hda_codec *codec, unsigned int scp_data)
>  		goto error;
>  
>  	/* OK, now check if the write itself has executed*/
> -	status = snd_hda_codec_read(codec, WIDGET_DSP_CTRL, 0,
> +	val = snd_hda_codec_read(codec, WIDGET_DSP_CTRL, 0,
>  				    VENDOR_DSPIO_STATUS, 0);
> +	put_unaligned_le32(val, &status);
> +
>  error:
>  	mutex_unlock(&spec->chipio_mutex);
>  
> -- 
> 1.7.4.1
>