This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- groovy' to 'verification-done-groovy'. If the problem still exists, change the tag 'verification-needed-groovy' to 'verification-failed- groovy'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: verification-needed-groovy -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1903596 Title: stack trace in kernel Status in linux package in Ubuntu: In Progress Status in linux source package in Xenial: Fix Released Status in linux source package in Bionic: Fix Released Status in linux source package in Focal: Fix Committed Status in linux source package in Groovy: Fix Committed Status in linux source package in Hirsute: In Progress Bug description: == SRU Justification == Whenever a buggy NAPI driver returns more than its budget, it will trigger a stack trace warning with: WARN_ON_ONCE(work > weight); The warning message looks like this : WARNING: CPU: 2 PID: 0 at /build/linux-hwe-ymdo11/linux-hwe-4.15.0/net/core/dev.c:5672 net_rx_action+0x276/0x3b0 This is not very useful for debugging purpose, since it does not tell you what's going on there. == Fix == * 427d5838e996 ("net: napi: remove useless stack trace") This patch will emit a message giving the function name, and a descriptive message like: NAPI poll function ath10k_pci_napi_poll+0x0/0x120 [ath10k_pci] returned 0, exceeding its budget of 64. This patch is a clean-cherry for all the releases except Xenial. For Xenial it will need to be applied with -C1 == Test == Test kernels can be found here: https://people.canonical.com/~phlin/kernel/lp-1903596-napi-warnon/ Please note that even though I tried to reproduce this on a XPS 13 9360 mentioned in this bug report that shipped with Atheros QCA6174 [168c:003e] wireless card, but I can't trigger this warning message. The bug opener is also unable to test this due to some other reasons. Howeve I did tried to trigger this warning forcibly by putting it outside the if statement with the test kernels in the following link to make sure it won't cause some other problem. https://people.canonical.com/~phlin/kernel/lp-1903596-napi-warnon /force-to-warn/ == Where problems could occur == For this bug itself, this patch does not really solve the problem but it will provide more debug information for developers in the future (and since this is just a warning message, it should be fine). We can expect to see more a detailed report against ath10k driver in the future on launchpad. == Original Bug Report == This appears to be a problem in the ath10k module. I am not sure what it is exactly. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-image-4.15.0-122-generic 4.15.0-122.124~16.04.1 ProcVersionSignature: Ubuntu 4.15.0-122.124~16.04.1-generic 4.15.18 Uname: Linux 4.15.0-122-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.26 Architecture: amd64 CurrentDesktop: Unity Date: Mon Nov 9 13:35:54 2020 DistributionChannelDescriptor: # This is a distribution channel descriptor # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor canonical-oem-somerville-xenial-amd64-20160624-2 InstallationDate: Installed on 2020-11-09 (0 days ago) InstallationMedia: Ubuntu 16.04 "Xenial" - Build amd64 LIVE Binary 20160624-10:47 SourcePackage: linux-signed-hwe UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1903596/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
