Re: [PATCH] regmap: allow to disable all locking mechanisms

From: Andy Shevchenko
Date: Sun Dec 10 2017 - 08:23:29 EST


On Wed, Dec 6, 2017 at 4:26 PM, Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
> We have a use case in the at24 EEPROM driver (recently converted to
> using regmap instead of raw i2c/smbus calls) where we read from/write
> to the regmap in a loop, while protecting the entire loop with
> a mutex.
>
> Currently this implicitly makes us use two mutexes - one in the driver
> and one in regmap. While browsing the code for similar use cases I
> noticed a significant number of places where locking *seems* redundant.
>
> Allow users to completely disable any locking mechanisms in regmap
> config.

> +static void regmap_lock_unlock_empty(void *__map)

..._none()?


> +{
> +
> +}
> +
> static void regmap_lock_mutex(void *__map)

> - if (config->lock && config->unlock) {
> + if (config->disable_locking) {
> + map->lock = map->unlock = regmap_lock_unlock_empty;
> + } else if (config->lock && config->unlock) {

Why not to introduce positive switch, namely
bool mutex_lock; // choose better name
and assign ..._none() by default?

--
With Best Regards,
Andy Shevchenko