| Summary: | [chv][regression][bisected] Brightness adjustment on Lenovo Miix 320-10ICR and Lenovo Miix2 8 is broken since Linux 5.3rc1 | ||
|---|---|---|---|
| Product: | DRI | Reporter: | russianneuromancer |
| Component: | DRM/Intel | Assignee: | Intel GFX Bugs mailing list <intel-gfx-bugs> |
| Status: | RESOLVED FIXED | QA Contact: | Intel GFX Bugs mailing list <intel-gfx-bugs> |
| Severity: | normal | ||
| Priority: | medium | CC: | chris, intel-gfx-bugs, thierry.reding |
| Version: | unspecified | ||
| Hardware: | x86-64 (AMD64) | ||
| OS: | Linux (All) | ||
| Whiteboard: | Triaged | ||
| i915 platform: | BSW/CHT | i915 features: | display/backlight |
| Attachments: | |||
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Description
russianneuromancer
2019-08-03 11:02:30 UTC
You should definitely mention what interface you are using to change the backlight. On Linux 5.0-5.2 I adjusted backlight via Gnome Shell slider in upper right corner. On Linux 5.3rc1+ this is no longer works, according to git bisect this is due to mentioned commit. That all I know right now. If I can provide more data from working/mom-working kernel - please let me know how to do so. [7.984343] [drm:intel_panel_vbt_fixed_mode [i915]] [CONNECTOR:105:DSI-1] using mode from VBT: [ 7.984387] [drm:drm_mode_debug_printmodeline [drm]] Modeline "1200x1920": 0 162980 1200 1280 1284 1344 1920 1980 1981 2021 0x8 0xa [ 7.984494] [drm:pwm_setup_backlight [i915]] *ERROR* Failed to own the pwm chip [ 7.984600] [drm:intel_panel_setup_backlight [i915]] failed to setup backlight for connector DSI-1 [ 7.984698] [drm:intel_dsi_get_hw_state [i915]] [ 7.984922] [drm:intel_modeset_readout_hw_state [i915]] [CRTC:47:pipe A] hw state readout: enabled @Chris, any suggestion here? Does this error give any clue? Two drivers for one bit of backlight HW, doomed to fail. If the acpi driver exposed a /sys/class/backlight, xf86-video-intel should have still found it. Created attachment 144959 [details] drm-tip dmesg with drm.debug=0x1e from Lenovo Miix2 8 As I just found same issue is reproducible on Lenovo Miix2 8 too. Attached log is from drm-tip 2019-08-05 (2bb7df95d4e058e61d9de39f1b97404592708d24) > If the acpi driver exposed a /sys/class/backlight, xf86-video-intel should have still found it. Lenovo Miix2 8, Lenovo Miix 320-10IRC On Linux 5.2 there is just one intel_backlight, adjusting brightness via intel_backlight works. Lenovo Miix2 8: On Linux 5.3 there is acpi_video0 and acpi_video1, echo values to brightness file in each one doesn't change backlight level. Lenovo Miix 320-10IRC: On Linux 5.3 there is... ~# ls /sys/class/backlight acpi_video0 acpi_video1 acpi_video2 acpi_video3 acpi_video4 acpi_video5 acpi_video6 acpi_video7 As with Lenovo Miix2 8, echo values to brightness file in each acpi_video doesn't change backlight level. For comparison below is logs from Linux 5.2.7 with drm.debug=0x1e and working backlight adjustment: Created attachment 144972 [details]
Linux 5.2.7 dmesg with drm.debug=0x1e from Lenovo Miix 320-10ICR
Created attachment 144973 [details]
Linux 5.2.7 dmesg with drm.debug=0x1e from Lenovo Miix2 8
Cc Thierry, committer of the regressing commit commit 4a6ef8e37c4d9a40f09438068da1734fd965bd75 Author: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de> Date: Wed Jun 12 10:36:07 2019 +0200 pwm: Add support referencing PWMs from ACPI Any thoughts? Per Thierry, the fix is [1], on its way to v5.3-rc4. Thanks for the report, closing. Please reopen if the problem persists with that commit. [1] https://kernel.googlesource.com/pub/scm/linux/kernel/git/thierry.reding/linux-pwm/+/6cf9481b440da6d6d86bd8e4c99a8b553b9d1271 Issue is no longer reproducible with Linux 5.3rc4. |
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