HeY Mark,
On 09-12-20, 13:34, Bard Liao wrote:
> sdw_update_slave_status will be invoked when a codec is attached,
> and the codec driver will initialize the codec with regmap functions
> while the codec device is pm_runtime suspended.
>
> regmap routines currently rely on regular SoundWire IO functions,
> which will call pm_runtime_get_sync()/put_autosuspend.
>
> This causes a deadlock where the resume routine waits for an
> initialization complete signal that while the initialization complete
> can only be reached when the resume completes.
>
> The only solution if we allow regmap functions to be used in resume
> operations as well as during codec initialization is to use _no_pm
> routines. The duty of making sure the bus is operational needs to be
> handled above the regmap level.
You okay these going thru sdw tree..?
>
> Fixes: 7c22ce6e21840 ('regmap: Add SoundWire bus support')
> Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
> ---
> drivers/base/regmap/regmap-sdw.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/base/regmap/regmap-sdw.c b/drivers/base/regmap/regmap-sdw.c
> index c92d614b4943..4b8d2d010cab 100644
> --- a/drivers/base/regmap/regmap-sdw.c
> +++ b/drivers/base/regmap/regmap-sdw.c
> @@ -11,7 +11,7 @@ static int regmap_sdw_write(void *context, unsigned int reg, unsigned int val)
> struct device *dev = context;
> struct sdw_slave *slave = dev_to_sdw_dev(dev);
>
> - return sdw_write(slave, reg, val);
> + return sdw_write_no_pm(slave, reg, val);
> }
>
> static int regmap_sdw_read(void *context, unsigned int reg, unsigned int *val)
> @@ -20,7 +20,7 @@ static int regmap_sdw_read(void *context, unsigned int reg, unsigned int *val)
> struct sdw_slave *slave = dev_to_sdw_dev(dev);
> int read;
>
> - read = sdw_read(slave, reg);
> + read = sdw_read_no_pm(slave, reg);
> if (read < 0)
> return read;
>
> --
> 2.17.1
--
~Vinod
