Hi Kai-Heng: Thank you for the response. Could we see this applied to 20.04 LTS (kernel 5.8) as we do not ship non-LTS releases.
To help ensure the safety of this patch, we did extensive testing throughout the weekend on 8 systems and 10 configurations. We found the following: 1. The ‘Patched’ kernel FIXED ALL ISSUES for all flickering panels 2. The 'Patched' kernel systems CONTINUED TO WORK WELL an additional 5 systems tested, all with different panels 3. The 'Unpatched' kernel almost always caused severe flickering for susceptible systems after a single sleep-wake cycle or after warm 4. We saw similar flickering regardless of which GFX driver was used. Flickering was eliminated on all when the patch was applied. The patch we provided and tested (https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1925685/+attachment/5491421/+files/drm-intel-both.patch ) combines the original patch with your proposed changes. We did this because applying both patches sequentially resulted in a minor conflict. We encourage you to try it to see for yourself. Your suggestion worked better than the original proposal, as it fixed ALL issues on affected systems. +---------------------------------------------------------------------------+ | Intel GFX Patch Test Results | +-----------+----------+---------+-----------------+------------+-----------+ | CPU | GPUs | Driver | Panel | Unpatched | Patched | +-----------+----------+---------+-----------------+------------+-----------+ | i7-10870H | i630 | Nouveau | LG Display | Bad Glitch | No Issues | | 3 Samples | RTX 3060 | (USB) | LP156WFG-SPB3 | + Flicker | | | | 3070 | | LGD Model 1573 | | | | | 3080 | | | | | +-----------+----------+---------+-----------------+------------+-----------+ | i7-10870H | i630 | Intel | LG Display | Bad Glitch | No Issues | | | RTX 3060 | (NVMe) | LP156WFG-SPB3 | + Flicker | | | | | | LGD Model 1573 | | | +-----------+----------+---------+-----------------+------------+-----------+ | i7-10870H | i630 | Nvidia | LG Display | Bad Glitch | No Issues | | | RTX 3060 | (NVMe) | LP156WFG-SPB3 | + Flicker | | | | | | LGD Model 1573 | | | +-----------+----------+---------+-----------------+------------+-----------+ | i7-10875H | i630 | Nouveau | LM156LF-1F02 | No Issues | No Issues | | | RTX 2060 | (USB) | NCP Model 75 | | | +-----------+----------+---------+-----------------+------------+-----------+ | i7-9750H | i630 | Nouveau | CMN N161HCA-GA1 | -- | No Issues | | | RTX 2070 | (USB) | | | | +-----------+----------+---------+-----------------+------------+-----------+ | i7-8750H | i630 | Nouveau | LGD Model 1472 | No Issues | No Issues | | | GTX 1060 | (USB) | | | | +-----------+----------+---------+-----------------+------------+-----------+ | i7-6700HQ | i530 | Nvidia | LGD Model 1135 | -- | No Issues | | | 970M | (NVMe) | | | | +-----------+----------+---------+-----------------+------------+-----------+ | i7-3720QM | HD 4000 | Intel | LEN Model 16562 | -- | No Issues | | | | (USB) | | | | +-----------+----------+---------+-----------------+------------+-----------+ Testing Notes 1. We ran all tests with 5 sleep-wake cycles with the Chrome browser running a 1080p video in one tab and a WebGL Aquarium in the other. 2. The 'Unpatched' kernel is 5.8.0-42-generic from the Ubuntu 20.04 LTS repository. 3. The ‘Patched’ kernel is 5.8.0-50-generic from the Ubuntu 20.04 LTS repository source with the above patch applied. We compiled packages and installed them in the test image. 4. We tested most systems using a live-session USB image. However, we tested some systems using an NVMe image so we could compare Intel and Nvidia drivers as well. 5. The OS used for all testing was Ubuntu 20.04.2 with the KDE desktop (Kubuntu 20.04.2). 6. We skipped testing 'Unpatched' kernels on older systems as what matters is that the 'Patched' kernel continues to work, which it does. Sincerely, Mike -- 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/1925685 Title: [SRU] Patch for flicker and glitching on certain hardware, intel framebuffer, Status in linux package in Ubuntu: Confirmed Status in linux source package in Bionic: Confirmed Status in linux source package in Focal: Confirmed Status in linux source package in Groovy: Confirmed Status in linux source package in Hirsute: Confirmed Bug description: Filing this with my Kubuntu Focus (kfocus.org) OEM hat on: [Impact] We are having screen flickering and glitching issues with some of our hardware upon wake from suspend. We have worked with our ODM to figure out a fix for this. They had reported there were no issues when running Windows on the same hardware. As such, we tested, and found that this issue first began as a regression in kernel 5.0 (did not exist in kernel 4.18 per our tests). We identified a patch via https://gitlab.freedesktop.org/drm/intel/-/issues/272 in which this has been solved. Per our testing by recompiling the kernel, this completely fixes our hardware issue. As of 4-21, this fix has been merged into the Linux kernel per Timo Aaltonen, and will be included in the kernel in the 5.13 release. Our hardware ships with Kubuntu 20.04 LTS, which means the 5.13 kernel will not see these machines, at least in the forseeable future. As such, we request that this patch be added to the kernel. Per our testing, this patch is straightforward to add and works flawlessly. Until this is fixed, we have a whole batch of hardware we cannot sell, so, as an OEM, this is a high priority. [Test Plan] * Install Kubuntu on an affected Kubuntu Focus M2 computer (not in the hands of customers at this time) * Notice screen glitching/flickering after wake-from-suspend. * Install kernel compiled with the attached patch. Boot from patched kernel. * Suspend laptop, resume. No glitches. [Where problems could occur] * Although this solves the problem for us and has been confirmed to work with the Intel developers that developed this patch, it could cause another display type to have problems. This is unlikely as it has been vetted by Intel and by the mainline Linux kernel developers. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1925685/+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
