Kernel Bug Tracker – Bug 14164
"Unknown boot option" warning message should not be printed for options which will be passed to kernel modules
Last modified: 2012-06-13 16:57:55 UTC
When passing a kernel parameter of the type:
the kernel will throw a warning message that says "Unknown boot option 'radeon.modeset=0'. Ignoring..." However, the parameter is not ignored, it is passed to (and parsed by) the radeon module.
We (Fedora QA/BugZappers) find people are often confused or worried by this message when we ask them to use such a parameter, and worry that it is not being applied correctly. The kernel should not print this warning/error message when the parameter is of a format that will cause it to be passed to a kernel module.
Is this because modern modprobe is scraping these options from /proc/cmdline? If so, yes, we should suppress those messages altogether.
CC'd Jon, he'd know.
I don't know how it's implemented, exactly, that may well be how it works. I just know that you can pass any module parameter as a kernel command line parameter in that format (modulename.moduleparameter=value) and it gets passed on somehow.
ping? this still regularly causes confusion for users when we're trying to debug various issues, see https://bugzilla.redhat.com/show_bug.cgi?id=538840#c3 for a recent example: it's a 'cosmetic' bug but with unfortunate effects.
Yea, exactly that's what happens. Modprobe pulls out those arguments and processes them.
I don't know why I missed this bug, but that should be fixed now. I even have daily reminders setup and should get CC'd on every module issue from now on.