I installed 4.15.0-56-generic to a bionic VM, with the -modules and -modules-extra packages. I went into /var/lib/modules/4.15.0-56/ and did a search for hibmc_drm. There was no mention apart from a header Makefile. The module was not built and not present on amd64.
I did the same for 5.0.0-22-generic in a disco VM, and the module was not built and was not present. 4.15.0-56-generic has been installed to a amd64 based Huawei server which was having the issues explained in this bug, and since the module was not present, the screen was not "blurry" when a desktop environment was installed and viewed from the remote access tool used by Huawei. To ensure that ARM64 still has the kernel module built, I also downloaded linux-modules-extra for 4.15.0-56-generic for ARM64. The hibmc_drm module is still present in /var/lib/modules/4.15.0-56/kernel/drivers/gpu/drm/hisilicon/hibmc This means that Huawei's arm64 based servers will not be affected by the change. The fixes solve the problems of the video mode not being right for amd64 based platforms, and does not cause any regressions for ARM64. I am happy to mark this as verified. ** Tags removed: verification-needed-bionic verification-needed-disco ** Tags added: verification-done-bionic verification-done-disco -- 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/1762940 Title: hibmc-drm Causes Unreadable Display for Huawei amd64 Servers Status in linux package in Ubuntu: Fix Committed Status in linux source package in Bionic: Fix Committed Status in linux source package in Disco: Fix Committed Status in linux source package in Eoan: Fix Committed Bug description: BugLink: https://bugs.launchpad.net/bugs/1762940 [Impact] amd64 based Huawei servers have problems where the display output of their iBMC chips is broken, resulting in a "blurry" screen when viewed from their in house remote kvm-like console. Example: https://launchpadlibrarian.net/365907668/creen_picture_for_blur.png The issue is caused by the hibmc_drm kernel module being loaded. The PCI ID for the iBMC chips on amd64 hardware is the same as arm64 hardware, but the hibmc_drm driver was developed only for use on arm64 hardware, most notably for the Huawei D05 development board. The impact to Huawei is that their customers cannot use Ubuntu server install media as the screen goes "blurry" when the d-i install media or subuqity installer loads the hibmc_drm kernel module after language selection. The only workaround for their customers is to press the "E" key during the very first installer menu and adding "modprobe.blacklist=hibmc_drm" to the kernel command line in the grub menu. This is not good for customer experience with their servers. Other problems exist for the hibmc_drm driver on amd64, such as working on bios, but not uefi, and not being wayland compatible, making the screen blurry whenever a desktop session is started and gdm loaded. Huawei have asked us to remove hibmc_drm from all architectures except arm64, and this aligns with advice from Hisilicon. [Fix] I modified the config/annotations file to remove all architectures except arm64, and created a patch for Kconfig to set a firm requirement on ARM64 for hibmc_drm. I will send the Kconfig patch upstream in the coming days for a more permanent fix. [Testcase] Apply the patches and run: ubuntu-bionic/CONFIGS$ fakeroot debian/rules genconfigs ubuntu-bionic/CONFIGS$ grep -Rin "hibmc" . ./arm64-config.flavour.generic:5739:CONFIG_DRM_HISI_HIBMC=m You should see that only arm64 has the config option enabled. A test kernel has been built, and is available here: https://launchpad.net/~mruffell/+archive/ubuntu/sf232667-test Huawei requested a test d-i install iso to test server install with, which can be found here and uses the kernel from the ppa above: https://people.canonical.com/~mruffell/sf232667_ubuntu_server_d-i_20190711b1.iso Both the test kernel and the custom d-i install iso have been tested on amd64 Huawei server hardware successfully and video output is functional. [Regression Potential] Regressions will be limited to hardware containing the iBMC chips from Hisilicon, which I believe are exclusive to Huawei servers. I have taken care to ensure that hibmc_drm is enabled for ARM64 so it should not impact kernels built for the Huawei D05 arm64 development board, and d-i will still load the hibmc_drm driver during startup for arm64. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1762940/+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
