On Mon, Dec 14, 2015 at 09:19:30AM +0100, Geert Uytterhoeven wrote: > Hi Paul, > > On Sun, Dec 13, 2015 at 2:41 AM, Paul Gortmaker > <paul.gortmaker@xxxxxxxxxxxxx> wrote: > > This series of commits is a slice of a larger project to ensure > > people don't have dead code for module removal in non-modular > > drivers. Overall there was roughly 5k lines of dead code in the > > kernel due to this. So far we've fixed several areas, like tty, > > x86, net, etc. and we continue to work on other areas. > > > > There are several reasons to not use module_init for code that can > > never be built as a module, but the big ones are: > > > > (1) it is easy to accidentally code up unused module_exit and remove code > > (2) it can be misleading when reading the source, thinking it can be > > modular when the Makefile and/or Kconfig prohibit it > > (3) it requires the include of the module.h header file which in turn > > includes nearly everything else. > > > > Here we convert some module_init() calls into device_initcall() and delete > > any module_exit and remove code that gets orphaned in the process, for > > an overall net code reduction, which is always welcome. > > > > The use of device_initcall ensures that the init function ordering > > remains unchanged, but one could argue that PCI host code might be more > > appropriate to be handled under subsys_initcall. Fortunately we can > > revisit making this extra change at a later date if desired; it does > > not need to happen now, and we reduce the risk of introducing > > regressions at this point in time by separating the two changes. > > > > Over half of the drivers changed here already explicitly disallowed any > > unbind operations. For the rest we make them the same, since there is > > not really any sensible use case to unbind any built-in bus support that > > I can think of. > > Personally, I think all of these should become tristate, so distro kernels > don't have to build in PCI(e) support for all SoCs. multi_v7_defconfig kernels > are becoming too big. > > That does not preclude making these modules un-unloadable, though. Most of these can't be made tristate as-is, because they use symbols that aren't exported. Many of those symbols can easily be exported, so its just a matter of getting the respective patches merged. I disagree with making the modules non-unloadable, though. I have a local branch with changes necessary to unload the host controller driver and it works just fine. Thierry
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