Re: [PATCH v2 0/5] Add device DM163 (led driver, matrix colors shield & display)

[Peter Maydell]

On Wed, 28 Feb 2024 at 12:06, Thomas Huth <thuth@redhat.com> wrote:
>
> On 28/02/2024 12.31, Inès Varhol wrote:
> > TLDR: how can I provide a test or an example?
> >
> > I've tested the display by running custom executables and
> > comparing to the result on the real board, but I don't
> > know how to test it using a QTest.

> I'd suggest to try to take a screenshot via QMP or HMP. If you need a third
> party binary to get something on the screen, it's maybe best to write an
> avocado test instead of a qtest. See for example
> tests/avocado/machine_m68k_nextcube.py - it takes a screenshot and then
> converts the console messages from it via Tessaract to text and looks for
> the expected strings there. Alternatively, have a look at
> tests/avocado/machine_s390_ccw_virtio.py - it boots a Linux in the guest
> that writes a string into the /dev/fb0 framebuffer, then takes a screendump
> and then tries to find the string in the file. The latter could maybe also
> be done via a qtest if you know how to set up the framebuffer without a
> guest kernel.

The other extremely popular approach for testing display devices
is "I looked at the screen while I was doing the development,
and it was fine" :-)

-- PMM