On 5/18/26 12:19 PM, Shashank Balaji wrote: > Commit "driver core: platform: set mod_name in driver registration" will set > struct device_driver's mod_name member for platform driver registration. For a > driver to be registered with its mod_name set, module_kset needs to be > initialized, which currently happens in a subsys_initcall in > param_sysfs_init(). > The tegra cbb drivers register themselves before module_kset init, in a > core_initcall. This works currently because lookup_or_create_module_kobject(), > which dereferences module_kset via kset_find_obj(), is not called if mod_name > is not set, which is the case now. > > So in preparation for the commit "driver core: platform: set mod_name in > driver registration", > move module_kset init to pure_initcall level, ensuring it happens before tegra > cbb driver registration. > > Suggested-by: Gary Guo <[email protected]> > Co-developed-by: Rahul Bukte <[email protected]> > Signed-off-by: Rahul Bukte <[email protected]> > Signed-off-by: Shashank Balaji <[email protected]> > --- > Patch 4 depends on this patch > --- > kernel/params.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/params.c b/kernel/params.c > index 74d620bc2521..ac088d4b09a9 100644 > --- a/kernel/params.c > +++ b/kernel/params.c > @@ -957,7 +957,7 @@ static int __init param_sysfs_init(void) > > return 0; > } > -subsys_initcall(param_sysfs_init); > +pure_initcall(param_sysfs_init); > > /* > * param_sysfs_builtin_init - add sysfs version and parameter >
The change looks ok to me functionality-wise. Sysfs is initialized earlier in do_basic_setup() and other code, such as classes_init(), calls kset_create_and_add() similarly early. One minor issue is that pure_initcall() was originally intended for static variable initialization. The file include/linux/init.h says: | /* | * A "pure" initcall has no dependencies on anything else, and purely | * initializes variables that couldn't be statically initialized. | * | * This only exists for built-in code, not for modules. | * Keep main.c:initcall_level_names[] in sync. | */ | #define pure_initcall(fn) __define_initcall(fn, 0) The patch stretches the intended use of pure_initcall() somewhat in this regard. However, other code already appears to do the same, so I guess this is ok. Additionally, I think it would be good to update the comment preceding param_sysfs_init(). It currently says: | /* | * param_sysfs_init - create "module" kset | * | * This must be done before the initramfs is unpacked and | * request_module() thus becomes possible, because otherwise the | * module load would fail in mod_sysfs_init. | */ I suggest changing it to something like follows: This must be done before any driver registration so that when a driver comes from a built-in module, the driver core can add the module under /sys/module and create the associated driver symlinks. -- Thanks, Petr
