[libcamera-devel] [PATCH] libcamera: camera_manager: Return EBUSY if enumerator exists

[Laurent Pinchart]

Hello,

On Mon, Jan 21, 2019 at 05:01:40PM +0100, Niklas Söderlund wrote:
> On 2019-01-21 11:41:26 +0000, Kieran Bingham wrote:
> > In the case that someone calls CameraManager::start() and it has already
> > started/enumerated, instead of returning -ENODEV, return -EBUSY.
> > 
> > Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> 
> While working with this on the cam utility it struck me, should we 
> return negative error codes from CameraManager? This faces the 
> application and it might be unexpected for it to receive a negative 
> error.

We have to standardize on error codes (and of course document them). Is
it unusual for libraries to return negative error codes ? I've been
working with the kernel for so long that it just seems natural to me :-)

> In any case this change matches our documentation and is a good change.
> 
> Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> 
> > ---
> >  src/libcamera/camera_manager.cpp | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp
> > index d76eaa7ace86..21cb36dcb9b5 100644
> > --- a/src/libcamera/camera_manager.cpp
> > +++ b/src/libcamera/camera_manager.cpp
> > @@ -76,7 +76,7 @@ CameraManager::~CameraManager()
> >  int CameraManager::start()
> >  {
> >  	if (enumerator_)
> > -		return -ENODEV;
> > +		return -EBUSY;
> >  
> >  	enumerator_ = DeviceEnumerator::create();
> >  	if (enumerator_->enumerate())

-- 
Regards,

Laurent Pinchart