Re: [PATCH v2] mux: mmio: Add suspend and resume support

[Thomas Richard <thomas.richard@bootlin.com>]

On 12/4/24 14:53, Andrew Davis wrote:
> On 9/11/24 3:53 AM, Thomas Richard wrote:
>> The status of each mux is read during suspend and stored in the private
>> memory of the mux_chip.
>> Then the state is restored during the resume.
>>
>> Signed-off-by: Thomas Richard <thomas.richard@bootlin.com>
>> ---
>> In this second version, as discussed with Peter, everything is done in
>> the
>> mmio-mux driver.
>> A mux_mmio_set() function was added, and used during suspend stage to get
>> the status of the of the muxes.
>> This status is stored in the private memory of the mux_chip.
>> ---
>> Changes in v2:
>> - Remove all modifications done in the mux subsystem
>> - Add a mux_mmio_set()
>> - Read the status of muxes during suspend and store in the private memory
>>    of the mux_chip.
> 
> Do you need this private memory? Since this is already using regmap, why
> not use the regmap cache, then you can restore all the values on resume
> with a simple call to regcache_sync().
The regmap can be set without cache.
As you inherit the regmap, you cannot assume that the cache is enabled.

Thomas