[libcamera-devel] [PATCH V2] libcamera: MediaDevice: Make MediaDevice::setupLink account for existing link flags

[Dan Scally]

> I'm still interested to know how you hit this?
> What platform are you testing on ?

x86, specifically a Lenovo Miix-510. I'm working with the surface-linux guys trying to get webcams working on Microsoft Surface and similar devices. We're either patching DSDT or using a bridge driver to connect the sensors to the cio2 infrastructure, but trying to take images using either cam or qcam threw the error that this clears (though media-ctl got past it).

With this patch in, my webcam's functional.




‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Thursday, 27 August 2020 12:48, Kieran Bingham <kieran.bingham at ideasonboard.com> wrote:

> +libcamera-devel
> 

> On 27/08/2020 12:11, Dan Scally wrote:
> 

> > Hi Kieran
> > 

> > > Git commit messages should aim to be wrapped at 72 chars, though it can
> > > be longer when it makes sense. (the above goes to 96).
> > 

> > > We can rewrap when applying though.
> > 

> > Mea culpa - I'll stick to the limit in future. Happy to do a V3 if you prefer, fixing that and the SoB.
> 

> No worries, I think it's ok.
> 

> Unless there's any comments from anyone else I have it fixed up locally
> already.
> 

> > > This is missing a Signed-off-by tag from you.
> > 

> > > Can you confirm you are happy to add the following please?
> > > (as per the DCO: https://www.libcamera.org/contributing.html)
> > 

> > > Signed-off-by: Dan Scally djrscally at protonmail.com
> > 

> > Yes, absolutely. Sorry - first time patching anything, knew I'd forget something!
> 

> no problem, Thank you for contributing!
> 

> I'm still interested to know how you hit this?
> What platform are you testing on ?
> 

> -----------------------------------------------------------------------------------------------------------------------------
> 

> Kieran
> 

> > Thanks
> > Dan
> > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> > On Thursday, 27 August 2020 11:42, Kieran Bingham kieran.bingham at ideasonboard.com wrote:
> > 

> > > Hi Dan,
> > 

> > > On 26/08/2020 17:05, Dan Scally wrote:
> > 

> > > > The setupLink function fails (ioctl returns EINVAL) when it passes the MEDIA_LNK_FL_ENABLE flag
> > > > to a link that is already flagged with MEDIA_LNK_FL_ENABLE and MEDIA_LNK_FL_IMMUTABLE. Contrast
> > > > to media-ctl's equivalent media_setup_link() which ORs the new flags with the existing values.
> > > > This patch modifies the behaviour of setupLink() to behave the same as media_setup_link() in
> > > > media-ctl.
> > 

> > > Git commit messages should aim to be wrapped at 72 chars, though it can
> > > be longer when it makes sense. (the above goes to 96).
> > 

> > > We can rewrap when applying though.
> > 

> > > > ref https://git.linuxtv.org/v4l-utils.git/tree/utils/media-ctl/libmediactl.c#n210
> > 

> > > This is missing a Signed-off-by tag from you.
> > 

> > > Can you confirm you are happy to add the following please?
> > > (as per the DCO: https://www.libcamera.org/contributing.html)
> > 

> > > Signed-off-by: Dan Scally djrscally at protonmail.com
> > 

> > > With that,
> > 

> > > Reviewed-by: Kieran Bingham kieran.bingham at ideasonboard.com
> > 

> > > Eeep, git-am had issue applying this mail, possibly due to utf
> > > formatting or such, but I've fixed up locally.
> > 

> > > With confirmation from Dan on the SoB, and another RB tag, I'll handle
> > > integration of this patch as I have it locally.
> > 

> > > 

> > 

> > > Kieran
> > 

> > > > Changelog:
> > 

> > > >     v2 - Simplified by removing the call to link() to fetch a link that's already passed as a parameter to the function.
> > > >     

> > 

> > > > 

> > 

> > > > 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 de18d57..007a45b 100644
> > > > --- a/src/libcamera/media_device.cpp
> > > > +++ b/src/libcamera/media_device.cpp
> > > > @@ -794,7 +794,7 @@ int MediaDevice::setupLink(const MediaLink *link, unsigned int flags)
> > > > linkDesc.sink.index = sink->index();
> > > > linkDesc.sink.flags = MEDIA_PAD_FL_SINK;
> > 

> > > > -   linkDesc.flags = flags;
> > 

> > > > -   linkDesc.flags = flags | (link->flags() & MEDIA_LNK_FL_IMMUTABLE);
> > > >     int ret = ioctl(fd_, MEDIA_IOC_SETUP_LINK, &linkDesc);
> > > >     if (ret) {
> > > >     

> > 

> > > > 

> > 

> > > > libcamera-devel mailing list
> > > > libcamera-devel at lists.libcamera.org
> > > > https://lists.libcamera.org/listinfo/libcamera-devel
> > 

> > > --
> > 

> > > Regards
> > 

> > > 

> > 

> > > Kieran
> 

> --
> 

> Regards
> 

> --------
> 

> Kieran

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