Despite some of the nondeterminism behind this bug, I believe I have bisected this bug to the following commit in the Ubuntu kernel tree: 14ebfcacaeb07b02235f2ea881fd6e34e3de0d6f .
More info is available on this commit here: https://git.launchpad.net/~ubuntu- kernel/ubuntu/+source/linux/+git/unstable/commit/?id=14ebfcacaeb07b02235f2ea881fd6e34e3de0d6f The commit text reads: > UBUNTU: [Config] enable Intel DMA remapping by default > BugLink: https://bugs.launchpad.net/bugs/1951440 > > We have tried in the past to enable CONFIG_INTEL_IOMMU_DEFAULT_ON and > CONFIG_INTEL_IOMMU_SCALABLE_MODE_DEFAULT_ON (starting with Jammy), but > there were multiple issues (especially with old hardware), so we ended > up disabling these options afterwards, see LP: #1971699. > > Considering that IOMMU is enabled by default in upstream kernels, > probably most of these issues are solved now (or old hardware has been > decommissioned). > > Moreover, having this enabled by default can prevent potential issues > with modern hardware and drivers (see for example LP #1958004). > > Acked-by: Philip Cox <[email protected]> > Acked-by: Andrei Gherzan <[email protected]> > Signed-off-by: Andrea Righi <[email protected]> The commit text even predicts that the commit may introduce problems with older hardware. Its predictions appear unfortunately accurate. Operating under the assumption that this commit introduced the bug, as a workaround, I have found that adding: intel_iommu=igfx_off to the GRUB_CMDLINE appears to resolve the issue for me. Unfortunately, there appears to be no relief in the newest kernels. I tried the latest daily build available here: https://kernel.ubuntu.com/mainline/daily/ ...and found that the issue still persists there with the default GRUB_CMDLINE. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2062951 Title: Random flickering with Intel i915 (Gen9 GPUs) on Linux 6.8 (Ubuntu 24.04) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2062951/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
