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kitakar5525 / chromeos-kernel-linux-surface

linux-surface kernel for chromiumos.
GNU General Public License v3.0
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BYT/CHT: backlight not adjustable when i915 is built-in (driver initialization order, pwm vs i915) #8

Open kitakar5525 opened 4 years ago

kitakar5525 commented 4 years ago

To adjust the backlight on Surface 3, we need to build i915 as not built-in but module. Maybe the cause of this problem is that i915 will be loaded too early when built as built-in.

For now, I have to build DRM_I915 and modules which depend on it as module.

- DRM_I915
  - CONFIG_HDMI_LPE_AUDIO
  - INTEL_IPTS
kitakar5525 commented 4 years ago

Link to issue:

As for this bug, as I tried to explain in comment 63, this has been (mostly) fixed for close to 2 years now, at least for configs which build the i915 driver as a module, as almost all generic distro kernels do. So with my Fedora distro contributor had on I consider this bug fixed.

So, in general, I guess it's hard to specify driver load order for built-in drivers. I want i915 to be built-in as on vanilla chromeos-4.19, but I can't untill the above issue is fixed also when i915 is built-in.

I'll keep my issue open to track the state of the above issue when i915 is built-in.

kitakar5525 commented 4 years ago

At least I won't fix this issue (and I'm not able to fix anyway). I'll see what will happen on the issue I linked.