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

[Johan Hovold]

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 at kernel.org>
Link: https://lore.kernel.org/lkml/ZoQjAWse2YxwyRJv@hovoldconsulting.com/

(or use Closes: if you prefer).

> Signed-off-by: Sibi Sankar <quic_sibis at 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.

Johan