[PATCH] usb: gadget: function: constify snd_pcm_ops structure

From: Gustavo A. R. Silva
Date: Fri Jul 07 2017 - 19:51:34 EST


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.

This issue was detected using Coccinelle and the following semantic patch:

@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 = { ... };

Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
---
drivers/usb/gadget/function/u_audio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
index 5dd73b9..d4caa21 100644
--- a/drivers/usb/gadget/function/u_audio.c
+++ b/drivers/usb/gadget/function/u_audio.c
@@ -354,7 +354,7 @@ static int uac_pcm_null(struct snd_pcm_substream *substream)
return 0;
}

-static struct snd_pcm_ops uac_pcm_ops = {
+static const struct snd_pcm_ops uac_pcm_ops = {
.open = uac_pcm_open,
.close = uac_pcm_null,
.ioctl = snd_pcm_lib_ioctl,
--
2.5.0