Bug 1321266
| Summary: | restore CONFIG_ACPI_REV_OVERRIDE_POSSIBLE to avoid regression on Dell XPS 13 | ||
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| Product: | [Fedora] Fedora | Reporter: | James Cimino <james.cimino.github> |
| Component: | kernel | Assignee: | Kernel Maintainer List <kernel-maint> |
| Status: | CLOSED WONTFIX | QA Contact: | Fedora Extras Quality Assurance <extras-qa> |
| Severity: | high | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 23 | CC: | arnaud.kleinveld, cribari, darkbasic, enrico.tagliavini, gansalmon, itamar, james.cimino.github, jonathan, kernel-maint, labbott, madhu.chinakonda, mchehab |
| Target Milestone: | --- | Keywords: | Regression |
| Target Release: | --- | ||
| Hardware: | x86_64 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2016-05-27 13:31:28 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | |||
| Bug Blocks: | 1313434 | ||
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Description
James Cimino
2016-03-25 06:29:03 UTC
There is a discussion of this regression on LWN. http://lwn.net/Articles/680324/ Summary: - CONFIG_ACPI_REV_OVERRIDE_POSSIBLE only affects Dell XPS 13. - The code in question sets a flag that causes the kernel to revert to its <= 4.2 behavior. - The code is gated behind a DMI check that only runs on the specific laptop. See also upstream bug. https://bugzilla.kernel.org/show_bug.cgi?id=114171 I don't think this is actually a pure kernel problem, a lot of userspace bits (mostly configs) are missing. First of all alsa-ucm should be installed and it's not, by default. Second an actual config matching laptops is missing. The actual config file[1] seems to be for a tablet. Result is jack detection (and automatic switch between speakers and headphones) is broken. [1] http://git.alsa-project.org/?p=alsa-lib.git;a=tree;f=src/conf/ucm/broadwell-rt286;hb=HEAD (In reply to Enrico Tagliavini from comment #2) > I don't think this is actually a pure kernel problem, > a lot of userspace bits (mostly configs) are missing. That's besides the point. Audio worked with previous kernels. Due to a kernel upgrade it is now broken. This is a regression with an easy and known fix: simply restore CONFIG_ACPI_REV_OVERRIDE_POSSIBLE. Fixing userspace bits is always welcome, but this should have been done in the first place when the kernel was modified (when CONFIG_ACPI_REV_OVERRIDE_POSSIBLE was removed). Sure agreed with it. I was just pointing out the primary source of the problem and that user space adjustment is needed more than a kernel code fix. The CONFIG_ACPI_REV_OVERRIDE_POSSIBLE could be switched off again when the userspace is actually fixed / updated / correctly configured to handled this hardware in I2S mode. I run Fedora 23 on a Dell XPS 13 notebook (model 9343, bios A07). Since I upgraded to kernel 4.4 I have no audio. I filed a bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1313434 The problem persisted even after I upgraded alsa-lib and alsa-ucm to version 1.1.1-1. I filed a bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1313434 This is my primary working machine and this bug has been causing me a lot of trouble. Laura Abbott and Justin Forbes: your input here would be appreciated. F23 was rebased to 4.5.y. |