Can not unload ath11k_pci and load it back

[Mark Herbert]

I've found similar bug files already - so not to create duplicates 
simply commented there

https://bugzilla.kernel.org/show_bug.cgi?id=214541

Exactly - hibernation means saving state on disk and resuming later, it 
is a very usefull feature when you are running out of battery and want 
to save your work.

Also one more point I've found - if MHI is configured in the kernel - 
the card is starting up on thr first boot and works. But if i configure 
MHI as a module - it does not. MHI module do load. So do  ath11k and 
ath11k_pci.  But the last ath11k dmesg says :

mhi mhi0: Wait for device to enter SBL or Mission mode

Exactly as if I  do rmmod/modprobe sequence.

I use latest BIOS from Dell (in fact upgrading 3.0.4 to 3.1.0 did not 
cange anythng) ,  and have tried multiple kernels. Stable 5.14 series 
and ath11k git tree (next and master-pending). Nothing helps.  Sometimes 
it woks out - I had couple of times successfully rmmod/modprobe 
ath11k_pci but it s a kind of random and very rare event ( I had it 2 
times only).

So for me it looks like an issue between MHI and ath11k , but 
ubfortunately my knowledge is not enough to propose any solution here.

On 07.10.2021 09:22, Kalle Valo wrote:
> Mark Herbert <mark.herbert42 at gmail.com> writes:
>
>> Dear ath11k team,
>>
>> The main issue is I can not hibernate and wake up my XPS 13 9310.  If
>> I keep module loaded it hibernate. Bu hangs on resume.
> Just to avoid confusions with terminology, with hibernate you mean
> storing the system state to a disk and completely powering off the
> laptop?
>
> I assume hibernation fails because ath11k keeps the firmware running
> during suspend and ath11k is not able to recover if the firmware is dead
> during resume.
>
> Can you file a bug about this, instructions here:
>
> https://wireless.wiki.kernel.org/en/users/drivers/ath11k/bugreport
>
>> If I unload module - it resumes OK but there is no chance to have WIFI
>> back without reboot.
>>
>> If I do rmmod ath11k_pci - it shows errors in dmesg:
>>
>> [   48.801504] ath11k_pci 0000:72:00.0: link down error during global reset
>> [   48.801700] DMAR: DRHD: handling fault status reg 2
>> [   48.801709] DMAR: [INTR-REMAP] Request device [0x72:0x00.0] fault
>> index 0x60 [fault reason 0x22] Present field in the IRTE entry is
>> clear
>>
>> If I do modprobe immediately it does load module but card will not
>> come back again.
>>
>> In Arch wiki reloading modules was explained as a workaround to
>> suspend-resume 9310, but looks like it does not work anymore. Suspend
>> to idle works fine - no module unloading needed.
> I have an XPS 13 9310 as well but I can't test this right now. Can you
> provide more information about the card not getting back after modprobe?
> What exact kernel and BIOS versions are you using? What log messages you
> get from ath11k? Preferably the exact commands you use and the output
> you get from ath11k would help a lot to understand what's happening.
>