[libcamera-devel] [PATCH] libcamera: media_device: Initialise local variable

[Laurent Pinchart]

Hi Kieran,

Thank you for the patch.

I'd rename the subject to "Fix uninitialized variable warning" or
something similar.

On Tue, Mar 19, 2019 at 11:35:32AM +0000, Kieran Bingham wrote:
> The local variable ifaceId generates a compiler warning that it is used
> without initialisation.

Could you specify the compiler version ?

> The loop, and check against the loop iterator, and the
> topology.num_interfaces actually ensures that this isn't the case, and
> that ifaceId can only be used when set to a valid ID.
> 
> The media_v2_interface.id field documents the ID as simply "Unique ID
> for the interface" but does not specify if zero is a valid ID or not. As
> such we don't further check the pre-initialised ID for validity and keep
> the existing check on the iterator count to determine if the ID had been
> discovered successfully.

I think we could still change that as the kernel ensures that entity IDs
start at 1, but I'll leave that up to you.

> Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

With the above fixed,

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> ---
>  src/libcamera/media_device.cpp | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/libcamera/media_device.cpp b/src/libcamera/media_device.cpp
> index ea4608932834..1e9024bf9721 100644
> --- a/src/libcamera/media_device.cpp
> +++ b/src/libcamera/media_device.cpp
> @@ -516,7 +516,7 @@ struct media_v2_interface *MediaDevice::findInterface(const struct media_v2_topo
>  {
>  	struct media_v2_link *links = reinterpret_cast<struct media_v2_link *>
>  						      (topology.ptr_links);
> -	unsigned int ifaceId;
> +	unsigned int ifaceId = 0;
>  	unsigned int i;
>  
>  	for (i = 0; i < topology.num_links; ++i) {

-- 
Regards,

Laurent Pinchart