Re: [PATCH V2 1/2] firmware: arm_scmi: Ensure that the message-id supports fastchannel

[Konrad Dybcio <konradybcio@kernel.org>]

On 4.09.2024 9:00 AM, Johan Hovold wrote:
> On Wed, Sep 04, 2024 at 08:43:23AM +0530, Sibi Sankar wrote:
>> Currently the perf and powercap protocol relies on the protocol domain
>> attributes, which just ensures that one fastchannel per domain, before
>> instantiating fastchannels for all possible message-ids. Fix this by
>> ensuring that each message-id supports fastchannel before initialization.
> 
> Please include the warnings that I reported seeing on x1e80100 and that
> this patch suppresses to the commit message:
> 
> arm-scmi firmware:scmi: Failed to get FC for protocol 13 [MSG_ID:6 / RES_ID:0] - ret:-95. Using regular messaging.
> arm-scmi firmware:scmi: Failed to get FC for protocol 13 [MSG_ID:6 / RES_ID:1] - ret:-95. Using regular messaging.
> arm-scmi firmware:scmi: Failed to get FC for protocol 13 [MSG_ID:6 / RES_ID:2] - ret:-95. Using regular messaging.
>  
>> Fixes: 6f9ea4dabd2d ("firmware: arm_scmi: Generalize the fast channel support")
> 
> And add:
> 
> Reported-by: Johan Hovold <johan+linaro@kernel.org>
> Link: https://lore.kernel.org/lkml/ZoQjAWse2YxwyRJv@hovoldconsulting.com/
> 
> (or use Closes: if you prefer).
> 
>> Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
>> ---
>>
>> v1:
>> * add missing MSG_SUPPORTS_FASTCHANNEL definition.
> 
> Unfortunately, this patch breaks resume from suspend on the x1e80100 crd:
> 
>         [   26.919676] CPU4: Booted secondary processor 0x0000010000 [0x511f0011]
>         [   26.960607] arm-scmi firmware:scmi: timed out in resp(caller: do_xfer+0x164/0x568)
>         [   26.987142] cpufreq: cpufreq_online: ->get() failed
> 
> and then the machine hangs (mostly, I saw an nvme timeout message after a
> while).
> 
> Make sure you test suspend as well as some of the warnings I reported
> only show up during suspend.

Eh it looks like PERF_LEVEL_GET (msgid 8) requires the use of FC, but
the firmware fails to inform us about it through BIT(0) in attrs..

Konrad