Public bug reported: The i915 driver in the Linux kernel misrepresents the max output of certain, newer, GPUs.
The output should be 16384x16384 for newer models (on at least 7th and 8th gen Intel CPUs) but it is stuck in 8192x8192. The problem lies in: https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/i915/intel_display.c The conditional branch which is wrong is: /* maximum framebuffer dimensions */ if (IS_GEN2(dev_priv)) { dev->mode_config.max_width = 2048; dev->mode_config.max_height = 2048; } else if (IS_GEN3(dev_priv)) { dev->mode_config.max_width = 4096; dev->mode_config.max_height = 4096; } else { dev->mode_config.max_width = 8192; dev->mode_config.max_height = 8192; } While I'm not certain which generations specifically allows the higher output it is most certainly true of all iGPUs on the 7th and 8th generation CPUs. This is corroborated by Intel's own hardware pages, and can be proven by running Wayland which ignores the limitation in the driver. Bug is present both on all Ubuntu releases, including 18.04. ** Affects: linux-signed-oem (Ubuntu) Importance: Undecided Status: New ** Tags: kernel-bug -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-signed-oem in Ubuntu. https://bugs.launchpad.net/bugs/1790390 Title: Intel i915 GPU driver has wrong max resolution output for certain models Status in linux-signed-oem package in Ubuntu: New Bug description: The i915 driver in the Linux kernel misrepresents the max output of certain, newer, GPUs. The output should be 16384x16384 for newer models (on at least 7th and 8th gen Intel CPUs) but it is stuck in 8192x8192. The problem lies in: https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/i915/intel_display.c The conditional branch which is wrong is: /* maximum framebuffer dimensions */ if (IS_GEN2(dev_priv)) { dev->mode_config.max_width = 2048; dev->mode_config.max_height = 2048; } else if (IS_GEN3(dev_priv)) { dev->mode_config.max_width = 4096; dev->mode_config.max_height = 4096; } else { dev->mode_config.max_width = 8192; dev->mode_config.max_height = 8192; } While I'm not certain which generations specifically allows the higher output it is most certainly true of all iGPUs on the 7th and 8th generation CPUs. This is corroborated by Intel's own hardware pages, and can be proven by running Wayland which ignores the limitation in the driver. Bug is present both on all Ubuntu releases, including 18.04. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-signed-oem/+bug/1790390/+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
