Librem 5: hang with cam -C1

[Jacopo Mondi]

On Wed, Mar 26, 2025 at 12:53:53PM +0100, Pavel Machek wrote:
> Hi!
>
> > > With -C100, it actually works, for both front and back cameras.
> >
> > great news \o/
>
> :). There's still bug somewhere, -C2 results in two buffer captured
> and exit, -C1 results in hang, which is quite confusing.

As Laurent mentioned the CSI-2 receiver driver might require a
min_queued_buffer of 2.

If you don't provide at least two buffers, streaming never starts.
I don't see it being specified in mainline imx8mq-mipi-csi2.c though
but my understanding is that you're on a very old kernel ?

>
> > > > I'm afraid a more detailed log is needed.
> > > > Run the above command with
> > > >
> > > > LIBCAMERA_LOG_LEVELS=0
> > > >
> > > > As librem5 has no ISP but a RAW sensor as far as I remember (I still
> > > > can't figure out what they were thinking when they selected this weird
> > > > combination) make sure you have the SimplePipelineHandler and
> > > > SoftwareISP compiled in and enabled.
> > >
> > > Yep, that's correct. I'm afraid combination of RAW sensor and no ISP
> >
> > In this specific case, the imx8mq SoC on the librem5 has no physical ISP
> >
> > > or no drivers for ISP is going to be common for a while in phone area
> > > :-(.
> >
> > That's why we're very glad to have the software ISP in libcamera and
> > see great improvements there from Milan and others ! ;)
>
> Yes, so... I'd like to take a stab at implementing autofocus in
> software ISP, as I understand that one is still missing.
>
> Any hints how to enable SoftwareISP?
>
> meson configure build says
>
> ipas               [ipu3, mali-c55,     [ipu3, mali-c55,     Select which IPA
>                       rkisp1, rpi/pisp,    rkisp1, rpi/pisp,   modules to build
>                       rpi/vc4, simple,     rpi/vc4, simple,
>                       vimc]                vimc]
> pipelines          [auto]               [all, auto,          Select which
>                                            imx8-isi, ipu3,     pipeline handlers to
>                                            mali-c55, rkisp1,   build. If this is
>                                            rpi/pisp, rpi/vc4,  set to "auto", all
>                                            simple, uvcvideo,   the pipelines
>                                            vimc, virtual]      applicable to the
>
> But I have no idea how if that's enough and what needs to be done at
> runtime.
>
> Thanks,
> 								Pavel
> --
> I don't work for Nazis and criminals, and neither should you.
> Boycott Putin, Trump, and Musk!


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