** Description changed: [Impact] A scary-looking message appears in dmesg in several places during boot: "Error parsing PCC subspaces from PCCT" + + This could cause users to believe they have buggy firmware, in cases + where it's actually fine. [Test Case] dmesg | grep "Error parsing PCC subspaces" [Fix] Resolved in upstream commit that cleanly cherry-picks back to bionic: 8f8027c5f935 mailbox: PCC: erroneous error message when parsing ACPI PCCT [Regression Risk] PCC is a generic ACPI-defined mechanism for the OS and firmware to communicate. Since the fix does change how the tables are parsed, regression scenarios could include breakages in PCC clients (things that use this layer to communicate to firmware). The only Kconfig option I see in bionic's source that depends on CONFIG_PCC is the CPPC library, which provides ACPI CPU performance management used by the cppc-cpufreq driver and is used by the scaling driver/governor for Sandy bridge processors. Tested on an Nvidia DGX system. This is an upstream fix, so any regressions will have upstream support.
-- 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/1528684 Title: Error parsing PCC subspaces from PCCT Status in linux package in Ubuntu: Confirmed Status in linux source package in Bionic: Confirmed Bug description: [Impact] A scary-looking message appears in dmesg in several places during boot: "Error parsing PCC subspaces from PCCT" This could cause users to believe they have buggy firmware, in cases where it's actually fine. [Test Case] dmesg | grep "Error parsing PCC subspaces" [Fix] Resolved in upstream commit that cleanly cherry-picks back to bionic: 8f8027c5f935 mailbox: PCC: erroneous error message when parsing ACPI PCCT [Regression Risk] PCC is a generic ACPI-defined mechanism for the OS and firmware to communicate. Since the fix does change how the tables are parsed, regression scenarios could include breakages in PCC clients (things that use this layer to communicate to firmware). The only Kconfig option I see in bionic's source that depends on CONFIG_PCC is the CPPC library, which provides ACPI CPU performance management used by the cppc-cpufreq driver and is used by the scaling driver/governor for Sandy bridge processors. Tested on an Nvidia DGX system. This is an upstream fix, so any regressions will have upstream support. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1528684/+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
