On Thu, 8 Oct 2020 at 21:17, Sudeep Holla <sudeep.ho...@arm.com> wrote: > > On Thu, Oct 08, 2020 at 04:37:18PM +0200, Etienne Carriere wrote: > > Remove the IDR replacement that prevent initializing an SCMI protocol > > when it has already been initialized. This is needed when there are > > several SCMI agents that do implement a given SCMI protocol unless > > what only the related SCMI protocol communication is initialized only > > for first probed agent. > > > > Can you please elaborate on your usecase please. What do you mean by several > SCMI agents here. OSPM is the only agent we are interested here. What > other agents is this driver supposed to handle here. We allocate memory > in init and calling init multiple times messes up the allocated and > initialised structures. > > So NACK for this patch as it needs more work if we need this at all. >
Hello Sudeep, Considering a device with several SCMI servers spread over several co-processor and possibly also in the Arm TZ secure world, each of these servers uses a specific SCMI channel. Without this change, each SCMI protocol gets initialized only for the first agent device that is probed. My setup is also a bit specific. My device has several secure configuration features that can individually be enabled or not. For example, configuring domain X as secure makes some clocks reachable by Linux only through SCMI, and configuring domain Y as secure makes other clocks reachable by Linux only through SCMI. For flexibility, I expose domain X resources (here clocks) to an Linux agent whereas domain Y resources (here clocks also) are exposed to another agent, each agent with its specific transport/channel. Enabling each agent node in the Linux FDT allows to define which SCMI clocks get exposed and hence registered in the kernel. Without the change proposed here, I cannot get the clocks exposed to both agents when enabled as the SCMI clock protocol is initialized only for the 1st probbed agent device. Regards, Etienne > -- > Regards, > Sudeep
