Displayport will not function currently with latest FW (1.04) and older Ubuntu (22.04). (Ubuntu 24.04 with any FW, or FW1.02 with any Ubuntu does not have this issue).
Nishant from AMD has root caused the issue, this is from him: There was a feature added to U-boot recently, configuring DP registers in U-boot and when kernel boots those registers are not in reset state. There is a patch in the latest kernel (6.8.-) to reset the DP IP. So, therefore bootfw 1.04 is working with Ubuntu24.04 but not with Ubuntu22.04. This patch fixes the issue: https://github.com/torvalds/linux/commit/be318d01a90366029e181068e8857c6252e1fadc I tried applying the patch to 22.04 and confirms that it fixes the issue. ** Description changed: - Displayport will not function currently with latest FW (1.04) and older - Ubuntu (22.04). (Ubuntu 24.04 with any FW, or FW1.02 with any Ubuntu - does not have this issue). + SRU Justification - Nishant from AMD has root caused the issue, this is from him: There was - a feature added to U-boot recently, configuring DP registers in U-boot - and when kernel boots those registers are not in reset state. There is a - patch in the latest kernel (6.8.-) to reset the DP IP. So, therefore - bootfw 1.04 is working with Ubuntu24.04 but not with Ubuntu22.04. + [Changes v1 -> v2] - This patch fixes the issue: - https://github.com/torvalds/linux/commit/be318d01a90366029e181068e8857c6252e1fadc + * Add <Where problems could occur> section + + [Impact] + + * DP is not working after v1.04 firmware update on Xilinx Kria boards + + [Fix] + + * Clean cherry-pick from upstream + * be318d01a903: drm: xlnx: dp: Reset DisplayPort IP - I tried applying the patch to 22.04 and confirms that it fixes the issue. + [Test Plan] + + * I hooked up a DP monitor to a KV260 with firmware v1.04 and Jammy + image installed, DP does not work before applying the patch, and works + after applying the patch. + + [Where problems could occur] + + * Very low potential for regression. This patch just asserts DisplayPort + reset signal before deasserting. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2114250 Title: Fix DP not working on Kria boards with 1.04 firmware (Jammy) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-xilinx-zynqmp/+bug/2114250/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
