On Thu, 04 Jan 2024 17:16:57 +0800 Jy Deng <1700011...@pku.edu.cn> wrote: > Package: src:linux > Version: 6.6.9-1 > Severity: normal > Tags: patch > X-Debbugs-Cc: 1700011...@pku.edu.cn > > Dear Maintainer, > > In short, current configuration of debian kernel makes some scaling governors > not usable, for example amd_pstate=passive Ondemand. Some small changes to > configuration can solve the problem. > > To sovle the problem there is two optional ways: > 1. Change some configurations like CONFIG_CPU_FREQ_GOV_POWERSAVE to y rather > than m > All the configuraion below needs to be chanegd to y: > CONFIG_CPU_FREQ_GOV_POWERSAVE=y > CONFIG_CPU_FREQ_GOV_USERSPACE=y > CONFIG_CPU_FREQ_GOV_ONDEMAND=y > CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y > > 2. Change the configuration CONFIG_MODULE_COMPRESS_XZ=y to > CONFIG_MODULE_COMPRESS_NONE=y > Notice that CONFIG_MODULE_COMPRESS_XZ=y not only breaks cpu frequency governors > but also breaks make bindeb-pkg. See > https://bugzilla.kernel.org/show_bug.cgi?id=218341 > So that choose this option can deal with this issue too. > > Two file attached is about the two ways above to fix the problem. > > > > Here is some explanation: > > Debian kernel used to set configuration as CONFIG_MODULE_COMPRESS_NONE=y. but > after 6.6 debian kernel configuration use CONFIG_MODULE_COMPRESS_XZ=y to > compress the kernel module. However, modules for cpu frequency governors is not > usable when it's module is compressed. > > For example, CONFIG_CPU_FREQ_GOV_POWERSAVE=m is fine to work if > CONFIG_MODULE_COMPRESS_NONE=y , but if CONFIG_MODULE_COMPRESS_XZ=y is set then > powersave governor is unavailable. This problem is same to other cpu frequency > governor configurations like CONFIG_CPU_FREQ_GOV_ONDEMAND=m > > On the other hand, configuration like CONFIG_CPU_FREQ_GOV_POWERSAVE=y build the > governor into kernel rather than module, so that such problem does not exist. > > Notice that such problem not only breaks scaling driver acpi-cpufreq, but also > breaks modules for example amd pstate.
Why do those config break when the compression config is enabled? That sounds like a bug in the kernel for those features, have you reported that upstream? At the very least, the configuration system should automatically set those to built-in, or refuse the wrong combination -- Kind regards, Luca Boccassi
