mesa: switch from i915 to i915g (gallium)

[tsndqst]

I made this change to get sway working on my EeePC 1005HA. I set WLR_NO_HARDWARE_CURSORS=1 before starting sway to get the mouse cursor to work. More information here.

Testing the changes

• I tested the changes in this PR: briefly

Local build testing

• I built this PR locally for my native architecture, (i686-glibc, native mode with a 32bit masterdir on x86-64)

[notramo]

It should be different package, because gallium version is more buggy than classic.
Classic is more reliable for Xorg and some less popular Wayland compositors, and gallium is only needed for wlroots which requires features that are missing from classic.

[tsndqst]

That makes sense. My quick and dirty change for my system won't be enough.

[ericonr]

Dang, what a mess :/

https://gitlab.freedesktop.org/mesa/mesa/-/issues/5418 says it will become default at some point, but we are clearly not there yet

I'd consider potentially a build option for the Void package until then, what do you think?

[q66]

my 2c: mesa 22 (coming in February) retires all the classic dri drivers anyway, so there is nothing much to deal with - we could just flip the switch, turn dri drivers off entirely, and be done with it

[ericonr]

My hope is that until February the Gallium driver will be (more) fixed, so doing the switch now would hurt a lot of users unnecessarily.

[q66]

any examples of how i915g is buggy in current releases?

(also, there's probably relatively few i915 users left at this point, since it's ancient hardware)

[Anachron]

Maybe we could revisit this? I'm a i915 user and with the recent mesa and linux combination I can't boot into X anymore.

[tsndqst]

I won't be much help beyond providing another data point. I am able to run X on my EeePC 1005HA with the latest Mesa 22 package.

@Anachron it might help to provide more information about your setup. Kernel version, /var/log/Xorg.0.log messages (especially if there are lines with (EE)) , etc.

Other folks may be able to provide more specific information about troubleshooting Mesa/X issues.

[tsndqst]

@Anachron are you using any Mesa environment variables to override behavior such as MESA_LOADER_DRIVER_OVERRIDE? https://docs.mesa3d.org/envvars.html#core-mesa-environment-variables

Perhaps the wrong driver is being selected. The i915 driver is gallium-only so there is no i915g driver anymore. i915 IS the gallium driver. In the past there was i915 and i915g.

[Anachron]

Turns out I had kernel boot parameters added before which are not supported with my i915 hardware anymore. Sorry for the noise.

[tsndqst]

I'm glad you figured it out.

Mesa has been updated to 22 now so I'm going to close this PR.