dell-precision-5560: init

[matdibu]

Description of changes

Added config for Dell Precision 5560

Things done

• Tested the changes in your own NixOS Configuration
• Tested the changes end-to-end by using your fork of nixos-hardware and importing it via <nixos-hardware> or Flake input: https://codeberg.org/mateidibu/nix-config/commit/00d5d6947d9e028c7cc7d1662f070635eeb84275

[matdibu]

I've also added a README

[matdibu]

@Mic92 what about this? I think it should at least be wrapped in a
lib.mkIf (config.hardware.intelgpu.driver == "i915")
but at that point, maybe it should be in common ?

[Mic92]

You are probably right.

Suggested change

	kernelParams = [ "i915.modeset=1" ];
	kernelParams = lib.mkIf (config.hardware.intelgpu.driver == "i915") [ "i915.modeset=1" ];

Also is this laptop not new enough to use xe anyway? Also isn't modset=1 the default since along time also?

lsmod | grep 'xe'
xe                   2875392  0
drm_gpuvm              45056  1 xe
drm_exec               12288  2 drm_gpuvm,xe
gpu_sched              65536  1 xe
drm_suballoc_helper    12288  1 xe
drm_ttm_helper         12288  1 xe
drm_buddy              20480  2 xe,i915
ttm                   102400  3 drm_ttm_helper,xe,i915
drm_display_helper    258048  2 xe,i915
cec                    73728  3 drm_display_helper,xe,i915
i2c_algo_bit           20480  2 xe,i915
video                  81920  2 xe,i915
backlight              28672  3 video,xe,i915

[matdibu]

it is, I left a note in the readme about using xe instead of i915
I simply don't know if we should default to that or not, since it's pretty new and might be less stable than i915

[matdibu]

also, I'm not sure about i915.modeset, I can see this locally:

$ modinfo i915 | grep modeset:
parm:           modeset:Use kernel modesetting [KMS] (0=disable, 1=on, -1=force vga console preference [default]) (int)

[matdibu]

are you on a precision5560 right now? I had to use force_probe to swap to xe

[matdibu]

fair enough, and thanks for reviewing btw!
but now I'm not sure the conditional in common/gpu/intel/tiger-lake/default.nix makes sense
could there be other tigerlake igpu device IDs that are whitelisted for xe? if not, maybe we should remove xe from that config

[matdibu]

I looked through the kernel sources for xe, found this struct:

static const struct xe_device_desc tgl_desc = {
        .graphics = &graphics_xelp,
        .media = &media_xem,
        PLATFORM(TIGERLAKE),
        .has_display = true,
        .has_llc = true,
        .require_force_probe = true,
};

so tigerlake has require_force_probe = true

[Mic92]

Seems like it, only LUNARLAKE and BATTLEMAGE will actually use the driver without force probe:

static const struct xe_device_desc lnl_desc = {
	PLATFORM(LUNARLAKE),
	.has_display = true,
};

static const struct xe_device_desc bmg_desc = {
	DGFX_FEATURES,
	PLATFORM(BATTLEMAGE),
	.has_display = true,
	.has_heci_cscfi = 1,
};

So we should probably adapt it for nixos-hardware as well.

[Mic92]

So this was introduced by @fidgetingbits in #944

[Mic92]

#1149