Re: [PATCH v2 17/25] media: solo6x10: Convert to generic PCM copy ops

[Hans Verkuil]

On 15/08/2023 21:01, Takashi Iwai wrote:
> This patch converts the solo6x10 driver code to use the new unified
> PCM copy callback.  It's a straightforward conversion from *_user() to
> *_iter() variants.  As copy_to_iter() updates the internal offest at
> each write, we can drop the dst counter update in the loop, too.
> 
> Note that copy_to_iter() returns the copied bytes, hence the error
> condition is adjusted accordingly.
> 
> Acked-by: Ismael Luceno <ismael@xxxxxxxxxxx>

Acked-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>

Regards,

	Hans

> Cc: Bluecherry Maintainers <maintainers@xxxxxxxxxxxxxxxxx>
> Cc: Anton Sviridenko <anton@xxxxxxxxxxxxxxxxxxx>
> Cc: Andrey Utkin <andrey_utkin@xxxxxxxxxxxx>
> Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
> Cc: linux-media@xxxxxxxxxxxxxxx
> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
> ---
>  drivers/media/pci/solo6x10/solo6x10-g723.c | 39 ++++------------------
>  1 file changed, 6 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/media/pci/solo6x10/solo6x10-g723.c b/drivers/media/pci/solo6x10/solo6x10-g723.c
> index 6cebad665565..1db9f40ee0c0 100644
> --- a/drivers/media/pci/solo6x10/solo6x10-g723.c
> +++ b/drivers/media/pci/solo6x10/solo6x10-g723.c
> @@ -204,9 +204,9 @@ static snd_pcm_uframes_t snd_solo_pcm_pointer(struct snd_pcm_substream *ss)
>  	return idx * G723_FRAMES_PER_PAGE;
>  }
>  
> -static int snd_solo_pcm_copy_user(struct snd_pcm_substream *ss, int channel,
> -				  unsigned long pos, void __user *dst,
> -				  unsigned long count)
> +static int snd_solo_pcm_copy(struct snd_pcm_substream *ss, int channel,
> +			     unsigned long pos, struct iov_iter *dst,
> +			     unsigned long count)
>  {
>  	struct solo_snd_pcm *solo_pcm = snd_pcm_substream_chip(ss);
>  	struct solo_dev *solo_dev = solo_pcm->solo_dev;
> @@ -223,35 +223,9 @@ static int snd_solo_pcm_copy_user(struct snd_pcm_substream *ss, int channel,
>  		if (err)
>  			return err;
>  
> -		if (copy_to_user(dst, solo_pcm->g723_buf, G723_PERIOD_BYTES))
> +		if (copy_to_iter(solo_pcm->g723_buf, G723_PERIOD_BYTES, dst) !=
> +		    G723_PERIOD_BYTES)
>  			return -EFAULT;
> -		dst += G723_PERIOD_BYTES;
> -	}
> -
> -	return 0;
> -}
> -
> -static int snd_solo_pcm_copy_kernel(struct snd_pcm_substream *ss, int channel,
> -				    unsigned long pos, void *dst,
> -				    unsigned long count)
> -{
> -	struct solo_snd_pcm *solo_pcm = snd_pcm_substream_chip(ss);
> -	struct solo_dev *solo_dev = solo_pcm->solo_dev;
> -	int err, i;
> -
> -	for (i = 0; i < (count / G723_FRAMES_PER_PAGE); i++) {
> -		int page = (pos / G723_FRAMES_PER_PAGE) + i;
> -
> -		err = solo_p2m_dma_t(solo_dev, 0, solo_pcm->g723_dma,
> -				     SOLO_G723_EXT_ADDR(solo_dev) +
> -				     (page * G723_PERIOD_BLOCK) +
> -				     (ss->number * G723_PERIOD_BYTES),
> -				     G723_PERIOD_BYTES, 0, 0);
> -		if (err)
> -			return err;
> -
> -		memcpy(dst, solo_pcm->g723_buf, G723_PERIOD_BYTES);
> -		dst += G723_PERIOD_BYTES;
>  	}
>  
>  	return 0;
> @@ -263,8 +237,7 @@ static const struct snd_pcm_ops snd_solo_pcm_ops = {
>  	.prepare = snd_solo_pcm_prepare,
>  	.trigger = snd_solo_pcm_trigger,
>  	.pointer = snd_solo_pcm_pointer,
> -	.copy_user = snd_solo_pcm_copy_user,
> -	.copy_kernel = snd_solo_pcm_copy_kernel,
> +	.copy = snd_solo_pcm_copy,
>  };
>  
>  static int snd_solo_capture_volume_info(struct snd_kcontrol *kcontrol,