[alsa-devel] [PATCH] topology: Fix the missing referenced elem ptr when merging private data

[Takashi Sakamoto]

Hi,

On Jul 21 2016 16:00, mengdong.lin at linux.intel.com wrote:
> From: Mengdong Lin <mengdong.lin at linux.intel.com>
> 
> tplg_copy_data() should set the valid referenced data element pointer.
> The caller will double check this pointer for all kinds of references,
> including TLV, controls, text and data.
> 
> Also fix an inaccurate dmesg.
> 
> Signed-off-by: Mengdong Lin <mengdong.lin at linux.intel.com>
> 
> diff --git a/src/topology/dapm.c b/src/topology/dapm.c
> index 4d343b2..e3c90d8 100644
> --- a/src/topology/dapm.c
> +++ b/src/topology/dapm.c
> @@ -201,7 +201,7 @@ static int tplg_build_widget(snd_tplg_t *tplg,
>  		}
>  
>  		if (!ref->elem) {
> -			SNDERR("error: cannot find control '%s'"
> +			SNDERR("error: cannot find '%s'"
>  				" referenced by widget '%s'\n",
>  				ref->id, elem->id);
>  			return -EINVAL;

It's better to split to two patches for the different aims. Accumulating
patches to log history is preferable, as long as you have concrete wills
to improve codes, I believe.

> diff --git a/src/topology/data.c b/src/topology/data.c
> index 768fc27..397f6a5 100644
> --- a/src/topology/data.c
> +++ b/src/topology/data.c
> @@ -1050,6 +1050,7 @@ int tplg_copy_data(snd_tplg_t *tplg, struct tplg_elem *elem,
>  		" element '%s'\n", ref->id, elem->id);
>  		return -EINVAL;
>  	}
> +	ref->elem = ref_elem;
>  
>  	tplg_dbg("Data '%s' used by '%s'\n", ref->id, elem->id);
>  	/* overlook empty private data */

I wonder why the assignment is done in this line. This function still
includes some codes to return errors. In this case, it's better to code
the assignment in last part of the function.

This is a public API. It's better not to touch application's objects in
invalid cases.


Regards

Takashi Sakamoto