[PATCH v3 0/5] drm/i915: eDP DPCD aux backlight fixes

From: Lyude Paul
Date: Thu Jan 16 2020 - 16:16:47 EST


I recently got a ThinkPad X1 Extreme 2nd Generation for fixing some
issues on, and noticed that out of the box the backlight doesn't work.
Along the way of fixing that, I found a few issues with how i915 handles
DPCD AUX backlight control and fixed them. Now I've got working
backlight controls, hooray!

Note that this patch series enables DPCD backlight controls by default.
This time however, we ignore the backlight type advertised in the VBT
(unless it's a custom backlight interface that doesn't use the standard
VESA interface over AUX) and just trust the DPCD.

Lyude Paul (5):
drm/i915: Fix eDP DPCD aux max backlight calculations
drm/i915: Assume 100% brightness when not in DPCD control mode
drm/i915: Fix DPCD register order in intel_dp_aux_enable_backlight()
drm/i915: Don't use VBT for detecting DPCD backlight controls
drm/i915: Auto detect DPCD backlight support by default

.../drm/i915/display/intel_display_types.h | 3 +
.../drm/i915/display/intel_dp_aux_backlight.c | 175 ++++++++++++------
drivers/gpu/drm/i915/i915_params.c | 2 +-
drivers/gpu/drm/i915/i915_params.h | 2 +-
4 files changed, 126 insertions(+), 56 deletions(-)

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2.24.1