Messages in this thread | | | Date | Thu, 3 Nov 2022 12:06:15 +0000 | From | Cristian Marussi <> | Subject | Re: [PATCH v4 0/11] Introduce a unified API for SCMI Server testing |
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On Thu, Nov 03, 2022 at 11:21:47AM +0000, Sudeep Holla wrote: > On Fri, Oct 28, 2022 at 07:38:25PM -0700, Florian Fainelli wrote: > > Hi Christian, > > > > On 10/19/2022 1:46 PM, Cristian Marussi wrote: > > [snip] > > > > > In V2 the runtime enable/disable switching capability has been removed > > > (for now) since still not deemed to be stable/reliable enough: as a > > > consequence when SCMI Raw support is compiled in, the regular SCMI stack > > > drivers are now inhibited permanently for that Kernel. > > > > For our platforms (ARCH_BRCMSTB) we would need to have the ability to start > > with the regular SCMI stack to satisfy if nothing else, all clock consumers > > otherwise it makes it fairly challenging for us to boot to a prompt as we > > purposely turn off all unnecessary peripherals to conserve power. We could > > introduce a "full on" mode to remove the clock provider dependency, but I > > suspect others on "real" silicon may suffer from the same short comings. > > > > Fair enough. But if we are doing SCMI firmware testing or conformance via > the $subject proposed way, can these drivers survive if the userspace do > a random or a torture test changing the clock configurations ? Not sure > how to deal with that as the intention here is to do the testing from the > user-space and anything can happen. How do we avoid bring the entire system > down while doing this testing. Can we unbind all the drivers using scmi on > your platform ? I guess no. Let me know. > > > Once user-space is reached, I suppose we could find a way to unbind from all > > SCMI consumers, and/or ensure that runtime PM is disabled, cpufreq is in a > > governor that won't do any active frequency switching etc. > > > > What do you think? > > Yes, Cristian always wanted to support that but I am the one trying to > convince him not to unless there is a strong requirement for it. You seem > to suggest that you have such a requirement, but that just opens loads of > questions and how to we deal with that. Few of them are as stated above, I > need to recall all the conversations I had with Cristian around that and why > handling it may be bit complex.
:D ... I really even more like the idea of enabling on demand full coexistence so that I completely delegate to the users to manually deal with possible interferences at runtime and drop any liabilities if someone shoots himself in the foot :P
... jokes apart I'll post today a V5 with a few fixes and and an optional coexistence mode so that Florian can experiment and see how much is feasible to operate in this way by manually unbinding/re-configuring SCMI behaviour at runtime before starting tests and not kill the system on something like ARCH_BRCMSTB platforms.
Thanks, Cristian
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