Created attachment 1682534 [details] kernel 5.5.17 working Since upgrading F31 to kernel-5.6.6-200.fc31.x86_64 I have no backlight control on my Cherry Trail tablet. It was working fine with the previous kernel kernel-5.5.17-200.fc31.x86_64. I have rebooted into 5.5.17-200 and the backlight is again working. I boot into 5.6.6-200 and it doesn't. It can be reproduced by selectively booting the above kernel versions. I haven't tried rawhide. I am not running any modules that not shipped with directly Fedora's kernel? 7. Please attach the kernel logs. You can get the complete kernel log for a boot with ``journalctl --no-hostname -k > dmesg.txt``. If the issue occurred on a previous boot, use the journalctl ``-b`` flag. Attached
Non working journalctl to be supplied shortly. Just need to reboot.
Created attachment 1682538 [details] kernel 5.6.6 not working
I noted this : $ uname -a Linux iota 5.6.6-200.fc31.x86_64 #1 SMP Tue Apr 21 15:34:22 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux $ dmesg | grep i915 [ 7.273289] i915 0000:00:02.0: vgaarb: deactivate vga console [ 7.276705] i915 0000:00:02.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=io+mem:owns=io+mem [ 7.277341] [drm:pwm_setup_backlight [i915]] *ERROR* Failed to configure the pwm chip <----- HERE [ 7.295743] [drm] Initialized i915 1.6.0 20200114 for 0000:00:02.0 on minor 0 [ 7.550745] fbcon: i915drmfb (fb0) is primary device [ 7.550756] i915 0000:00:02.0: fb0: i915drmfb frame buffer device I've used this tablet with Fedora for years and actually it's pretty well supported usually :-)
Thank you for the bugreport. This is a weird bug, normally if there is an issue we fail to get a reference to the PWM controller. Here we do get the reference, but then we fail to configure the PWM controller. I've prepared a test-kernel which makes the error somewhat more verbose. Can you please install that kernel and provide the new version of the "*ERROR* Failed to configure the pwm chip" error? Here is the test-kernel: https://koji.fedoraproject.org/koji/taskinfo?taskID=43939522 And here are some instructions for directly installing a kernel from koji: https://fedorapeople.org/~jwrdegoede/kernel-test-instructions.txt
Hi Hans and thankyou! $ uname -a Linux iota 5.6.8-300.rhbz1828927.fc32.x86_64 #1 SMP Thu Apr 30 13:10:11 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux $ dmesg | grep -i i915 [ 7.680755] i915 0000:00:02.0: vgaarb: deactivate vga console [ 7.684331] i915 0000:00:02.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=io+mem:owns=io+mem [ 7.684971] [drm:pwm_setup_backlight [i915]] *ERROR* Failed to configure the SoC pwm chip: -16 [ 7.699734] [drm] Initialized i915 1.6.0 20200114 for 0000:00:02.0 on minor 0 [ 7.965207] fbcon: i915drmfb (fb0) is primary device [ 7.965215] i915 0000:00:02.0: fb0: i915drmfb frame buffer device I had a look through the rest of the dmesg and there wasn't anything else seemed relevant in addition but please do let me know if I can do anything else. Regards, Matthew.
Thank you for giving the test kernel a try. The error code points to an issue in the pwm-lpss driver, which however has not changed at all in 5.6 ... I've prepared a new test kernel with a bit of a hack which might help and more importantly with a bunch of debugging dev_err calls added to help debug this. At the moment this is building here: This takes about 1 - 2 hours to complete. After this has completed building please install the new test kernel, boot into it and then do: dmesg --level=err This should give a whole bunch of debug messages, put these in a file like this: dmesg --level=err > dmesg.log And then attach the generated dmesg.log here please. It would also be interesting to know if controlling the backlight now works, please try changing the brightness setting. After changing the brightness please collect a new log: dmesg --level=err > dmesg2.log And also attach that here.
Oops, I forgot to put in the link to the new test-kernel build, it is: https://koji.fedoraproject.org/koji/taskinfo?taskID=43952987
Thanks again.... I've installed that latest test kernel : $ uname -a Linux iota 5.6.8-300.rhbz1828927_2.fc32.x86_64 #1 SMP Thu Apr 30 21:37:16 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux $ cat /proc/cmdline BOOT_IMAGE=(hd0,gpt2)/vmlinuz-5.6.8-300.rhbz1828927_2.fc32.x86_64 root=/dev/mapper/fedora_localhost--live-root ro resume=/dev/mapper/fedora_localhost--live-swap rd.lvm.lv=fedora_localhost-live/root rd.lvm.lv=fedora_localhost-live/swap rhgb quiet $ dmesg --level=err [ 8.070876] pwm-lpss 80862288:00: initial state 0xffffffff period 52 duty_cycle 0 enabled 1 [ 8.070898] pwm-lpss 80862288:00: PWM_SW_UPDATE is set before update [ 8.070903] pwm-lpss 80862288:00: prepare 0xffffffff -> 0xff00a000 [ 15.702936] pwm-lpss 80862288:00: prepare 0x800044af -> 0xc000a0c5 [ 16.457480] Bluetooth: hci0: unexpected event for opcode 0xfc2f [ 25.962319] intel_atomisp2_pm 0000:00:03.0: can't change power state from D3cold to D0 (config space inaccessible) And I'm happy to report that changing the brightness does now work :-) And for each brightness change I see the additional logs (one per change in brightness : [ 52.237394] pwm-lpss 80862288:00: prepare 0x8000a0c5 -> 0xc000a066 [ 53.341512] pwm-lpss 80862288:00: prepare 0x8000a066 -> 0xc000a0d4 [ 61.265888] pwm-lpss 80862288:00: prepare 0x8000a0d4 -> 0xc000a07d [ 62.112195] pwm-lpss 80862288:00: prepare 0x8000a07d -> 0xc000a0cc [ 172.298136] pwm-lpss 80862288:00: prepare 0x8000a0cc -> 0xc000a03b [ 173.238337] pwm-lpss 80862288:00: prepare 0x8000a03b -> 0xc000a0c5 Hope it's ok but I'm going to refrain from using attachments as it's not all that verbose. Best regards, Matthew.
Ok, good news I think I've found the problem. I've prepared a 5.6.12 kernel build with a patch added which should fix this: https://koji.fedoraproject.org/koji/taskinfo?taskID=44412267 At the moment this is building, this takes about 1 - 2 hours to complete. Generic install instructions are still here: https://fedorapeople.org/~jwrdegoede/kernel-test-instructions.txt This kernel again will error out on the "PWM_SW_UPDATE is set before update" error which my previous test kernel ignored (as a test hack). This contains a fix so that the "PWM_SW_UPDATE is set before update" error should no longer happen. Please give this kernel a test run when it has completed building. This kernel still includes a patch for additional debug output. I would appreciate it if you can copy and paste that debug output here like last time (no need to attach it if it is not too much lines).
Yes, good news indeed! Please see below, all working as you predicted :-) $ uname -a Linux iota 5.6.12-300.rhbz1828927.fc32.x86_64 #1 SMP Tue May 12 11:39:36 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux $ cat /proc/cmdline BOOT_IMAGE=(hd0,gpt2)/vmlinuz-5.6.12-300.rhbz1828927.fc32.x86_64 root=/dev/mapper/fedora_localhost--live-root ro resume=/dev/mapper/fedora_localhost--live-swap rd.lvm.lv=fedora_localhost-live/root rd.lvm.lv=fedora_localhost-live/swap rhgb quiet $ dmesg --level=err [ 7.814451] pwm-lpss 80862288:00: initial state 0x800044af period 50198 duty_cycle 15748 enabled 1 [ 7.814467] pwm-lpss 80862288:00: prepare 0x800044af -> 0xc000a000 [ 16.016919] pwm-lpss 80862288:00: prepare 0x8000a000 -> 0xc000a0f3 [ 17.001309] Bluetooth: hci0: unexpected event for opcode 0xfc2f [ 27.311559] intel_atomisp2_pm 0000:00:03.0: can't change power state from D3cold to D0 (config space inaccessible) [ 27.317509] intel_atomisp2_pm 0000:00:03.0: can't change power state from D3cold to D0 (config space inaccessible) and then once for each change in brightness (i.e. four changes shown here) : [ 182.529432] pwm-lpss 80862288:00: prepare 0x8000a0f3 -> 0xc000a097 [ 183.854494] pwm-lpss 80862288:00: prepare 0x8000a097 -> 0xc000a0ca [ 184.835755] pwm-lpss 80862288:00: prepare 0x8000a0ca -> 0xc000a07b [ 185.769006] pwm-lpss 80862288:00: prepare 0x8000a07b -> 0xc000a0d2 Many thanks again for continuing to work on this! Best regards, Matthew.
Thank you for testing the fix. I've submitted the fix upstream and added it as downstream patch to the Fedora kernels for now. The fix will be included in the next official Fedora kernel build.
FEDORA-2020-57bf620276 has been submitted as an update to Fedora 32. https://bodhi.fedoraproject.org/updates/FEDORA-2020-57bf620276
FEDORA-2020-0c0b5d9004 has been submitted as an update to Fedora 31. https://bodhi.fedoraproject.org/updates/FEDORA-2020-0c0b5d9004
FEDORA-2020-320f05784e has been submitted as an update to Fedora 30. https://bodhi.fedoraproject.org/updates/FEDORA-2020-320f05784e
FEDORA-2020-0c0b5d9004 has been pushed to the Fedora 31 testing repository. In short time you'll be able to install the update with the following command: `sudo dnf upgrade --enablerepo=updates-testing --advisory=FEDORA-2020-0c0b5d9004` You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2020-0c0b5d9004 See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.
FEDORA-2020-57bf620276 has been pushed to the Fedora 32 testing repository. In short time you'll be able to install the update with the following command: `sudo dnf upgrade --enablerepo=updates-testing --advisory=FEDORA-2020-57bf620276` You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2020-57bf620276 See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.
FEDORA-2020-320f05784e has been pushed to the Fedora 30 testing repository. In short time you'll be able to install the update with the following command: `sudo dnf upgrade --enablerepo=updates-testing --advisory=FEDORA-2020-320f05784e` You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2020-320f05784e See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.
FEDORA-2020-57bf620276 has been pushed to the Fedora 32 stable repository. If problem still persists, please make note of it in this bug report.
FEDORA-2020-5436586091 has been pushed to the Fedora 31 testing repository. In short time you'll be able to install the update with the following command: `sudo dnf upgrade --enablerepo=updates-testing --advisory=FEDORA-2020-5436586091` You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2020-5436586091 See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.
FEDORA-2020-5436586091 has been pushed to the Fedora 31 stable repository. If problem still persists, please make note of it in this bug report.