| Summary: | [VLV, backlight] Backlight Brighness not linear | ||||||
|---|---|---|---|---|---|---|---|
| Product: | DRI | Reporter: | Egbert Eich <eich> | ||||
| Component: | DRM/Intel | Assignee: | Intel GFX Bugs mailing list <intel-gfx-bugs> | ||||
| Status: | CLOSED FIXED | QA Contact: | Intel GFX Bugs mailing list <intel-gfx-bugs> | ||||
| Severity: | normal | ||||||
| Priority: | medium | CC: | f.de.kruijf, intel-gfx-bugs | ||||
| Version: | unspecified | ||||||
| Hardware: | x86-64 (AMD64) | ||||||
| OS: | Linux (All) | ||||||
| Whiteboard: | |||||||
| i915 platform: | BYT | i915 features: | display/backlight | ||||
| Attachments: |
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(In reply to Egbert Eich from comment #0) > Created attachment 122698 [details] > kernel log w drm.debug=0x6 > > We've received a report that the backlight brightness behaves non-linear on > a VLV > (PCI DevID: 0x0f31) with kernel 4.5 or any eariler kernel. Driver seems to > use the vlv_*_backlight() functions. > > The brightness range is: 0 - 7812. > Written to /sys/class/backlight/intel_backlight/brignness 0 and 7812 give > black, 1 and 4687 both give full brightness. We seem to have neglected the bug a bit, apologies. Egbert Eich, since There were improvements pushed in kernel that will benefit to your system, so please re-test with latest kernel and mark as REOPENED if you can reproduce (and attach fresh gpu error dump & kernel log) and RESOLVED/* if you cannot reproduce. (In reply to yann from comment #1) > (In reply to Egbert Eich from comment #0) > > Created attachment 122698 [details] > > kernel log w drm.debug=0x6 > > > > We've received a report that the backlight brightness behaves non-linear on > > a VLV > > (PCI DevID: 0x0f31) with kernel 4.5 or any eariler kernel. Driver seems to > > use the vlv_*_backlight() functions. > > > > The brightness range is: 0 - 7812. > > Written to /sys/class/backlight/intel_backlight/brignness 0 and 7812 give > > black, 1 and 4687 both give full brightness. > > We seem to have neglected the bug a bit, apologies. > > Egbert Eich, since There were improvements pushed in kernel that will > benefit to your system, so please re-test with latest kernel and mark as > REOPENED if you can reproduce (and attach fresh gpu error dump & kernel log) > and RESOLVED/* if you cannot reproduce. Timeout - assuming resolved+fixed. If problem still persist with the latest kernels (preferable drm-tip from git://anongit.freedesktop.org/git/drm-tip), reopen this bug with latest logs as attachments. |
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Created attachment 122698 [details] kernel log w drm.debug=0x6 We've received a report that the backlight brightness behaves non-linear on a VLV (PCI DevID: 0x0f31) with kernel 4.5 or any eariler kernel. Driver seems to use the vlv_*_backlight() functions. The brightness range is: 0 - 7812. Written to /sys/class/backlight/intel_backlight/brignness 0 and 7812 give black, 1 and 4687 both give full brightness.