Re: [PATCH v2] media: v4l2-async: Add waiting subdevices debugfs

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Hi Ezequiel,

On Tue, Jan 05, 2021 at 10:34:14AM -0300, Ezequiel Garcia wrote:
> Hi Sakari, Laurent,
> 
> On Tue, 2021-01-05 at 05:46 +0200, Laurent Pinchart wrote:
> > Hi Ezequiel,
> > 
> > Thank you for the patch.
> > 
> > On Mon, Jan 04, 2021 at 02:48:40PM -0300, Ezequiel Garcia wrote:
> > > There is currently little to none information available
> > > about the reasons why a v4l2-async device hasn't
> > > probed completely.
> > > 
> > > Inspired by the "devices_deferred" debugfs file,
> > > add a file to list information about the subdevices
> > > that are on waiting lists, for each notifier.
> > > 
> > > This is useful to debug v4l2-async subdevices
> > > and notifiers, for instance when doing device bring-up.
> > > 
> > > For instance, a typical output would be:
> > > 
> > > $ cat /sys/kernel/debug/video4linux/pending_async_subdevices
> > > ipu1_csi1:
> > >  [fwnode] dev=20e0000.iomuxc-gpr:ipu1_csi1_mux, node=/soc/bus@2000000/iomuxc-gpr@20e0000/ipu1_csi1_mux
> > > ipu1_csi0:
> > >  [fwnode] dev=20e0000.iomuxc-gpr:ipu1_csi0_mux, node=/soc/bus@2000000/iomuxc-gpr@20e0000/ipu1_csi0_mux
> > > imx6-mipi-csi2:
> > >  [fwnode] dev=1-003c, node=/soc/bus@2100000/i2c@21a4000/camera@3c
> > > imx-media:
> > > 
> > > Note that match-type "custom" prints no information.
> > > Since there are no in-tree users of this match-type,
> > > the implementation doesn't bother.
> > 
> > I wonder if we should drop it.
> > 
> 
> That would make sense, unless we have some out-of-tree
> users, and we want to support that.
> 
> Sakari, what do you think?

I think we could drop it. But I'd do that in a separate patch from this
one.

-- 
Regards,

Sakari Ailus