Re: [PATCH 6/7] ASoC: SDCA: Device boot into the system suspend process

[Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>]

On 12/11/25 12:59, Charles Keepax wrote:
> On Tue, Dec 09, 2025 at 12:18:09PM +0000, Pierre-Louis Bossart wrote:
>> On 11/25/25 15:21, Charles Keepax wrote:
>>> +	/*
>>> +	 * FDL has to run from the system resume handler, at which point
>>> +	 * pm_runtime isn't yet active.
>>> +	 */
>>
>> aren't there cases where FDL also needs to run in a pm_runtime
>> resume case?
> 
> Potentially, depends if someone builds a system that does that.
> 
>> My understanding of FDL is that the host would *always* check
>> if the device lost context and if firmware is required then the
>> download takes place. I am not sure why we need the assumption
>> that firmware is *only* required for system resume?
> 
> Mostly because it seems that is pretty standard for PC systems,
> to only drop rails on hibernate.
> 
> But the primary issue I have is the "check if the device lost
> context" part. I don't see a good way to implement that under
> SDCA. If we figure out a good way to do that then most of my
> objections to allowing the firmware download on runtime resume
> go away.

Wondering if the 'Needs_Initialization' bit could be used but not only initialization writes but firmware as well?
it could be device-specific, but IIRC that was one way to check if context was lost or not.

And there are other bits that tell you if the function was reset, see Function_has_been_reset in the Function_Status control.