Hi Javier,

On Fri, Jun 9, 2023 at 11:59 AM Javier Martinez Canillas
[off-list ref] wrote:

Thomas Zimmermann [off-list ref] writes:

quoted

quoted

quoted

I'd also question the argument that there's even fbdev userspace out
there. It was never popular in it's heyday and definitely hasn't
improved since then. Even the 3 people who still ask for fbdev support

There's X.org, DirectFB, SDL, ...

None of these examples has a dependency on fbdev. They can freely switch
backends and have moved to DRM. Anything program utilizing these
examples has no dependency on fbdev either.

When I say "userspace" in this context, it's the one old program that
supports nothing but fbdev. TBH I'm having problems to come up with
examples.

I personally have two real world examples that can give to you :)

1) I've a IoT device at home that has a bunch of sensors (temperatury,
   humidity, etc) and a SSD1306 display panel to report that. It just
   has small fbdev program to print that info. I could probably port
   to KMS but didn't feel like it. Found a fbdev program that I could
   modify and got the job done.

2) I built a portable retro console for my kids, that uses a ST7735R
   LCD panel. The software I use is https://www.retroarch.com/ which
   uses fbdev by default (I believe that supports a KMS mode but out
   of the box it works with fbdev and that's better tested by them.

So even when I'm not interested and don't want to enable any of the
fbdev drivers, I want to use the ssd130x and st7735r DRM drivers and
the DRM fbdev emulation layer.

In other words, there's real use cases for supporting fbdev programs
with DRM drivers. Now, I agree with this patch-set and probably will
disable the user-space fbdev interface in Fedora, but on my embedded
projects I will probably keep it enabled.

That's why I think that we should support the following combinations:

* fbdev drivers + DRM fbdev emulation + fbdev user-space

"fbdev drivers + fbdev user-space", I assume?

* only DRM drivers without fbdev emulation nor fbdev user-space (your series)

Thomas' series includes fbdev emulation here, for the text console.

* only DRM fbdev emulation + fbdev user-space enabled (FB_CORE)

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds