[BRLTTY] ‘empty console’

[Sebastian Humenda]

Hi Nicolas

Nicolas Pitre schrieb am Tue, Nov 26, 2019 at 04:44:42PM -0500:
> On Tue, 26 Nov 2019, Sebastian Humenda wrote:
> > Nicolas Pitre schrieb am Sun, Nov 17, 2019 at 02:09:52PM -0500:
> > > On Sun, 17 Nov 2019, Sebastian Humenda wrote:
> > > > I have now had a chance to find out more about the issue. I can reproduce this
> > > > both on a Debian 10 with Linux 4.19, or 5.2, as well as on an Ubuntu with
> > > > Linux 5.3.
> > > > As a temporary work-around, I have set the console font from „fixed” to
> > > > terminus in the largest font. I wonder how this might affect /dev/vcsu.
> > >
> > > Are you saying that this workaround "solved" the issue?
> >
> > Yes, it does.
>
> I'm baffled.
>
> What does "stty -a" give you, with and without the font change? More
> specifically, what are the reported rows and columns values on the first
> output line?

Font size 8 x 16 (non-frame buffer font)

speed 38400 baud; rows 90; columns 320; line = 0;

From small to large, the smallest working font size is  11 x 22, terminus:

speed 38400 baud; rows 65; columns 232; line = 0;

> > > What if you add the following to your brltty.conf instead:
> > >
> > > screen-parameters lx:unicode=no
> >
> > Then I get "no screen" on my display.
>
> This is even stranger.  Do you have both the /dev/vcsa and /dev/vcsu
> devices present on your system when that happens?

Yes, they are both present.

> > > What messages related to "Console" or "framebuffer" or "fb0" do you get
> > > from the dmesg command after boot?
> >
> > I've attached the output below. Hopefully this is helpful at all, it was a bit
> > tedious to grep for three different terms :).
>
> You may do:
>
> $ dmesg | grep -i "console\|framebuffer\|fb0"

I thought that the context of these lines might be helpful :).

Thanks
Sebastian