[PATCH 09/17] ASoC: Intel: avs: Add ROM requests

[Cezary Rojewski]

On 2022-02-25 2:42 AM, Pierre-Louis Bossart wrote:
> On 2/7/22 06:21, Cezary Rojewski wrote:
>> ROM requests are messages initiated by Host to alter firmware early boot
>> process. They specify whether the next boot should be a fresh start or if
>> IMR can be used to speed things up.
> 
> 'can' is an imprecise term in technical documentation.
> 
> did you mean 'shall' (requirement), 'may' (permission) or 'should'
> (recommendation)?
> 
> It's my understanding that it's legal to redo a complete reboot from a
> clean-slate.
> 
> It's also unclear if the firmware can use this mechanism to prevent the
> use of IMR, e.g. if in some firmware builds state save/restore was
> disabled for some reason.


This is a very good feedback, indeed I miss out on the 'can' vs 'shall' 
(and similar) quite often when speaking about hw/fw procedures. Thank 
you for paying attention, Pierre.

Yes, in this case driver has total control over the procedure and 
chooses which method to use when booting the DSP.

While I can't say the details, closed-source firmware (from APL and 
onwards) is built with IMR in mind. By that I mean that it assumes IMR 
is always present. So I believe such scenario - having save/restore 
disabled - is not possible here.