[Bug 1864698] Re: Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4, but 5.3 works

** Changed in: linux (Ubuntu Focal) Status: Confirmed => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1864698 Title: Can't change laptop-screen brightness on Dell XPS 13 9370 wi

[Bug 1864698] Re: Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4, but 5.3 works

Hi, I confirm that fixes it! Thanks. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1864698 Title: Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4, but 5.3 works To manag

[Bug 1864698] Re: Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4, but 5.3 works

@ricab, This should be fixed in the latest focal kernel, 5.4.0-21.25. Can you please retest and confirm? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1864698 Title: Can't change laptop-screen brig

[Bug 1864698] Re: Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4, but 5.3 works

Here is a new test kernel which not only revert the quirk, but introduce a new way to quirk the panels which support DPCD backlight https://people.canonical.com/~acelan/bugs/lp1861521/ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. h

[Bug 1864698] Re: Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4, but 5.3 works

A test kernel can be found here: https://people.canonical.com/~khfeng/lp1864698/ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1864698 Title: Can't change laptop-screen brightness on Dell XPS 13 937

[Bug 1864698] Re: Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4, but 5.3 works

** Description changed: + === SRU Justification === + [Impact] + Brightness on XPS 9370 can't be changed. + + [Fix] + Revert the regression commit, which matches to XPS 9730's panel. + + [Test] + After reverting the commit and tested an XPS 9370 at my hand, the + backlight sysfs interface start

[Bug 1864698] Re: Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4, but 5.3 works

screw that, -16 was tested with the same result -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1864698 Title: Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4, but 5.3 work

[Bug 1864698] Re: Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4, but 5.3 works

actually, 5.4.0-14 is missing a commit which might fix this -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1864698 Title: Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4,

[Bug 1864698] Re: Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4, but 5.3 works

this is a regression caused by a distro patch, will be fixed soon ** Changed in: linux (Ubuntu) Assignee: (unassigned) => AceLan Kao (acelankao) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1864

[Bug 1864698] Re: Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4, but 5.3 works

** Summary changed: - Can't change laptop-screen brightness on Dell XPS 13 9370 + Can't change laptop-screen brightness on Dell XPS 13 9370 with kernel 5.4, but 5.3 works ** Tags added: regression-release ** Tags added: champagne rls-ff-incoming -- You received this bug notification because y

[Bug 1864698] Re: Can't change laptop-screen brightness on Dell XPS 13 9370

You're right, just booted into 5.3 (which was still installed) and the problem is gone. I did not install any mainline kernel yet. Let me know if you still need that, along with instructions and a specific version please. -- You received this bug notification because you are a member of Ubuntu B

[Bug 1864698] Re: Can't change laptop-screen brightness on Dell XPS 13 9370

It sounds like a possible regression in kernel 5.4. Can you try an older or newer kernel? https://kernel.ubuntu.com/~kernel-ppa/mainline/ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1864698 Title:

[Bug 1864698] Re: Can't change laptop-screen brightness on Dell XPS 13 9370

** Summary changed: - Can't change laptop-screen brightness + Can't change laptop-screen brightness on Dell XPS 13 9370 ** Package changed: xorg (Ubuntu) => linux (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.