[libcamera-devel] [PATCH 05/11] libcamera: v4l2_controls: Fix usage of strerror()

[Laurent Pinchart]

Hi Jacopo,

Thank you for the patch.

On Mon, Mar 09, 2020 at 05:24:08PM +0100, Jacopo Mondi wrote:
> On failure, the return code from V4L2Device::ioctl() is the negative error
> code set by the failed ::ioctl() system call. When the return code of
> V4L2Device::ioctl() is provided to strerror() it has to be negated again
> to obtain the positive error code. Fix a few wrong usages of the return
> code which provided to the strerror() function a negative error code.
> 
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>

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

This is an independent bug fix, feel free to push it already.

> ---
>  src/libcamera/v4l2_device.cpp | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
> index 98639bd0f07f..179476e9afad 100644
> --- a/src/libcamera/v4l2_device.cpp
> +++ b/src/libcamera/v4l2_device.cpp
> @@ -201,13 +201,13 @@ int V4L2Device::getControls(ControlList *ctrls)
>  		/* Generic validation error. */
>  		if (errorIdx == 0 || errorIdx >= count) {
>  			LOG(V4L2, Error) << "Unable to read controls: "
> -					 << strerror(ret);
> +					 << strerror(-ret);
>  			return -EINVAL;
>  		}
>  
>  		/* A specific control failed. */
>  		LOG(V4L2, Error) << "Unable to read control " << errorIdx
> -				 << ": " << strerror(ret);
> +				 << ": " << strerror(-ret);
>  		count = errorIdx - 1;
>  		ret = errorIdx;
>  	}
> @@ -291,13 +291,13 @@ int V4L2Device::setControls(ControlList *ctrls)
>  		/* Generic validation error. */
>  		if (errorIdx == 0 || errorIdx >= count) {
>  			LOG(V4L2, Error) << "Unable to set controls: "
> -					 << strerror(ret);
> +					 << strerror(-ret);
>  			return -EINVAL;
>  		}
>  
>  		/* A specific control failed. */
>  		LOG(V4L2, Error) << "Unable to set control " << errorIdx
> -				 << ": " << strerror(ret);
> +				 << ": " << strerror(-ret);
>  		count = errorIdx - 1;
>  		ret = errorIdx;
>  	}

-- 
Regards,

Laurent Pinchart