On Tue, May 19, 2020 at 9:19 PM Arnd Bergmann <[email protected]> wrote: > > On Sat, May 16, 2020 at 12:13 PM Baolin Wang <[email protected]> wrote: > > > > Some platforms such as Spreadtrum platform, define a special method to > > update bits of the registers instead of reading and writing, which means > > we should use a physical regmap bus to define the reg_update_bits() > > operation instead of the MMIO regmap bus. > > > > Thus add a a __weak function for the syscon driver to allow to register > > a physical regmap bus to support this new requirement. > > > > }; > > > > +struct regmap * __weak syscon_regmap_init(struct device_node *np, > > + void __iomem *base, > > + struct regmap_config > > *syscon_config) > > +{ > > + return regmap_init_mmio(NULL, base, syscon_config); > > +} > > + > > Sorry, I don't think the __weak function is going to help here. I'm not > sure whether it actually does what you want when both syscon and > sprd_syscon are loadable modules (I would guess not), but it clearly > won't work when syscon is built-in and sprd_syscon is a module, and > even if the module loader knows how to resolve __weak symbols,
I happened to see module.c last week. It seems there's some code to handle weak symbols by checking about STB_WEAK. But it is not in this case. When syscon.c is built-in and sprd_syscon is module, this would not work because the __weak one has been built into kernel already. Maybe live patch feature may work it out. But it seems over expensive to do things like this. > I would not want to rely on module load ordering to make it behave > the right way. Agree. All other sprd modules would must be loaded behind sprd_syscon and this will not be handled by modprobe. Thanks to pointing out this. Best, Orson > > Arnd
