Re: [PATCH] wifi: wilc1000: Keep slot powered on during suspend/resume

[Marek Vasut <marex@denx.de>]

On 9/5/24 9:27 AM, Kalle Valo wrote:
> Marek Vasut <marex@denx.de> writes:
> 
>>>>> Are you also taking into account hibernation? During hibernation the
>>>>> device will be powered off. I can't remember the details right now but
>>>>> wanted to mention this.
>>>>
>>>> I don't think I am. Isn't hibernation actually a full shutdown, so the
>>>> hardware does get reinitialized ?
>>> I don't know how it works exactly nor what you exactly mean with
>>> reinitalized.
>>
>> My understanding is that hibernation is suspend-to-disk, isn't it ?
> 
> Yes, that's what I mean.
> 
>> (that's not something that is even available on my hardware)
> 
> Yeah, I'm guessing wilc1000 is used more in embedded enviroments where
> hibernation is not really an important, it's used more in laptops. So I
> guess it won't be a big problem if wilc1000 doesn't support hibernation
> but please try to keep it in mind still.
> 
>> Doesn't the hardware get completely turned OFF during suspend-to-disk
>> and then turned ON (and therefore initialized again) on
>> resume-from-disk?
> 
> I'm not sure how it works exactly but my experience is that for
> hibernation a driver cannot assume that the firmware is running during
> resume.
> 
>>> But at least with ath11k hibernation didn't work when it
>>> left the firmware running during suspend.
>>
>> Is there a thread on lore or some details of this you could point me to?
> 
> See commit 166a490f59ac ("wifi: ath11k: support hibernation") and the
> commits before that. I'm sure that there's more info about hibernation
> but don't have any pointers.

Ah, thank you.

The firmware reloading support should be addressed by some sort of 
future variant of patch Ajay sent as attachment in [1], that should then 
also deal with the hibernation part. I asked them to post the patch 
properly to the ML.

What about this patch, it fixes suspend/resume for me and with a fix to 
the atmel controller I suggested to Alexis in this thread, it should not 
have any adverse effects .

[1] 
https://lore.kernel.org/all/2bbdc690-aec5-4a11-893e-01270c6d5b84@microchip.com/