Re: [PATCH v2 1/5] pinctrl: Allow modules to use pinctrl_[un]register_mappings

From: Hans de Goede
Date: Wed Jan 01 2020 - 08:04:48 EST


On 30-12-2019 14:31, Linus Walleij wrote:
On Mon, Dec 16, 2019 at 9:51 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:

Currently only the drivers/pinctrl/devicetree.c code allows registering
pinctrl-mappings which may later be unregistered, all other mappings
are assumed to be permanent.

Non-dt platforms may also want to register pinctrl mappings from code which
is build as a module, which requires being able to unregister the mapping
when the module is unloaded to avoid dangling pointers.

To allow unregistering the mappings the devicetree code uses 2 internal
functions: pinctrl_register_map and pinctrl_unregister_map.

pinctrl_register_map allows the devicetree code to tell the core to
not memdup the mappings as it retains ownership of them and
pinctrl_unregister_map does the unregistering, note this only works
when the mappings where not memdupped.

The only code relying on the memdup/shallow-copy done by
pinctrl_register_mappings is arch/arm/mach-u300/core.c this commit
replaces the __initdata with const, so that the shallow-copy is no
longer necessary.

After that we can get rid of the internal pinctrl_unregister_map function
and just use pinctrl_register_mappings directly everywhere.

This commit also renames pinctrl_unregister_map to
pinctrl_unregister_mappings so that its naming matches its
pinctrl_register_mappings counter-part and exports it.

Together these 2 changes will allow non-dt platform code to
register pinctrl-mappings from modules without breaking things on
module unload (as they can now unregister the mapping on unload).

Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>

This v2 works fine for me, I applied it to this immutable branch in the
pinctrl tree:

And pulled that into the pinctrl "devel" branch for v5.6.

Please pull this immutable branch into the Intel DRM tree and apply
the rest of the stuff on top!

Great, thank you!




Happy New year everyone.