I haven't had a chance to try these out and I'm not sure how to track these changes through the various repositories and branches but for the record there are some other commits in drm/i915 that are claimed to fix the issue. I'll report back when I get a chance to patch these into 5.3.0-40-generic (which, as a side note, fixes the black screen after resuming from suspend issue on the P1 Gen 2).
fde7266fb2f6 drm/i915: Fix eDP DPCD aux max backlight calculations
79946723092b drm/i915: Assume 100% brightness when not in DPCD control mode
662884a9ad99 drm/i915: Fix DPCD register order in intel_dp_aux_enable_backlight()
9ac7d53d70a2 drm/i915: Auto detect DPCD backlight support by default
d2a4bb6f8bc8 drm/i915: Don't use VBT for detecting DPCD backlight controls
I haven't had a chance to try these out and I'm not sure how to track these changes through the various repositories and branches but for the record there are some other commits in drm/i915 that are claimed to fix the issue. I'll report back when I get a chance to patch these into 5.3.0-40-generic (which, as a side note, fixes the black screen after resuming from suspend issue on the P1 Gen 2).
fde7266fb2f6 drm/i915: Fix eDP DPCD aux max backlight calculations aux_enable_ backlight( )
79946723092b drm/i915: Assume 100% brightness when not in DPCD control mode
662884a9ad99 drm/i915: Fix DPCD register order in intel_dp_
9ac7d53d70a2 drm/i915: Auto detect DPCD backlight support by default
d2a4bb6f8bc8 drm/i915: Don't use VBT for detecting DPCD backlight controls
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https:/ /gitlab. freedesktop. org/drm/ intel/issues/ 510#note_ 387666
https:/ /github. com/torvalds/ linux/commit/ fde7266fb2f6fff 2a7fe861474bf19 8ef0f2449f /github. com/torvalds/ linux/commit/ 79946723092bde3 18ff11b3e57a02b a13a30b17e /github. com/torvalds/ linux/commit/ 662884a9ad99224 0b8169624aae1b0 cc273edc30 /github. com/torvalds/ linux/commit/ 9ac7d53d70a2b4f 43360e3aa0f14a2 514339328f /github. com/torvalds/ linux/commit/ d2a4bb6f8bc8cf2 d788adf7e59b5b5 2fe3a3333c
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