Re: [alsa-devel] [PATCH] ALSA: usb: constify snd_pcm_ops structures

[Clemens Ladisch]

Julia Lawall wrote:
> Check for snd_pcm_ops structures that are only stored in the ops field of a
> snd_soc_platform_driver structure or passed as the third argument to
> snd_pcm_set_ops.  The corresponding field or parameter is declared const,
> so snd_pcm_ops structures that have this property can be declared as const
> also.
>
> The semantic patch that makes this change is as follows:
> (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @r disable optional_qualifier@
> identifier i;
> position p;
> @@
> static struct snd_pcm_ops i@p = { ... };
>
> @ok1@
> identifier r.i;
> struct snd_soc_platform_driver e;
> position p;
> @@
> e.ops = &i@p;
>
> @ok2@
> identifier r.i;
> expression e1, e2;
> position p;
> @@
> snd_pcm_set_ops(e1, e2, &i@p)
>
> @bad@
> position p != {r.p,ok1.p,ok2.p};
> identifier r.i;
> struct snd_pcm_ops e;
> @@
> e@i@p
>
> @depends on !bad disable optional_qualifier@
> identifier r.i;
> @@
> static
> +const
>  struct snd_pcm_ops i = { ... };
> // </smpl>
>
> Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>

Acked-by: Clemens Ladisch <clemens@xxxxxxxxxx>

> ---
>  sound/usb/6fire/pcm.c           |    2 +-
>  sound/usb/caiaq/audio.c         |    2 +-
>  sound/usb/hiface/pcm.c          |    2 +-
>  sound/usb/misc/ua101.c          |    4 ++--
>  sound/usb/usx2y/usx2yhwdeppcm.c |    2 +-
>  5 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/sound/usb/6fire/pcm.c b/sound/usb/6fire/pcm.c
> index 36f4115..224a6a5 100644
> --- a/sound/usb/6fire/pcm.c
> +++ b/sound/usb/6fire/pcm.c
> @@ -555,7 +555,7 @@ static snd_pcm_uframes_t usb6fire_pcm_pointer(
>  	return ret;
>  }
>
> -static struct snd_pcm_ops pcm_ops = {
> +static const struct snd_pcm_ops pcm_ops = {
>  	.open = usb6fire_pcm_open,
>  	.close = usb6fire_pcm_close,
>  	.ioctl = snd_pcm_lib_ioctl,
> diff --git a/sound/usb/hiface/pcm.c b/sound/usb/hiface/pcm.c
> index 2c44139..23e66ed 100644
> --- a/sound/usb/hiface/pcm.c
> +++ b/sound/usb/hiface/pcm.c
> @@ -511,7 +511,7 @@ static snd_pcm_uframes_t hiface_pcm_pointer(struct snd_pcm_substream *alsa_sub)
>  	return bytes_to_frames(alsa_sub->runtime, dma_offset);
>  }
>
> -static struct snd_pcm_ops pcm_ops = {
> +static const struct snd_pcm_ops pcm_ops = {
>  	.open = hiface_pcm_open,
>  	.close = hiface_pcm_close,
>  	.ioctl = snd_pcm_lib_ioctl,
> diff --git a/sound/usb/usx2y/usx2yhwdeppcm.c b/sound/usb/usx2y/usx2yhwdeppcm.c
> index 90766a9..1f28cb2a 100644
> --- a/sound/usb/usx2y/usx2yhwdeppcm.c
> +++ b/sound/usb/usx2y/usx2yhwdeppcm.c
> @@ -587,7 +587,7 @@ static int snd_usX2Y_usbpcm_close(struct snd_pcm_substream *substream)
>  }
>
>
> -static struct snd_pcm_ops snd_usX2Y_usbpcm_ops =
> +static const struct snd_pcm_ops snd_usX2Y_usbpcm_ops =
>  {
>  	.open =		snd_usX2Y_usbpcm_open,
>  	.close =	snd_usX2Y_usbpcm_close,
> diff --git a/sound/usb/misc/ua101.c b/sound/usb/misc/ua101.c
> index c19a5dd..71a0e9e 100644
> --- a/sound/usb/misc/ua101.c
> +++ b/sound/usb/misc/ua101.c
> @@ -890,7 +890,7 @@ static snd_pcm_uframes_t playback_pcm_pointer(struct snd_pcm_substream *subs)
>  	return ua101_pcm_pointer(ua, &ua->playback);
>  }
>
> -static struct snd_pcm_ops capture_pcm_ops = {
> +static const struct snd_pcm_ops capture_pcm_ops = {
>  	.open = capture_pcm_open,
>  	.close = capture_pcm_close,
>  	.ioctl = snd_pcm_lib_ioctl,
> @@ -903,7 +903,7 @@ static struct snd_pcm_ops capture_pcm_ops = {
>  	.mmap = snd_pcm_lib_mmap_vmalloc,
>  };
>
> -static struct snd_pcm_ops playback_pcm_ops = {
> +static const struct snd_pcm_ops playback_pcm_ops = {
>  	.open = playback_pcm_open,
>  	.close = playback_pcm_close,
>  	.ioctl = snd_pcm_lib_ioctl,
> diff --git a/sound/usb/caiaq/audio.c b/sound/usb/caiaq/audio.c
> index 8f66ba7..af5ad84 100644
> --- a/sound/usb/caiaq/audio.c
> +++ b/sound/usb/caiaq/audio.c
> @@ -338,7 +338,7 @@ unlock:
>  }
>
>  /* operators for both playback and capture */
> -static struct snd_pcm_ops snd_usb_caiaq_ops = {
> +static const struct snd_pcm_ops snd_usb_caiaq_ops = {
>  	.open =		snd_usb_caiaq_substream_open,
>  	.close =	snd_usb_caiaq_substream_close,
>  	.ioctl =	snd_pcm_lib_ioctl,