Messages in this thread | | | Date | Mon, 12 Oct 2020 10:32:12 +0100 | From | Sudeep Holla <> | Subject | Re: [PATCH 1/5] firmware: arm_scmi: always initialize protocols |
| |
On Fri, Oct 09, 2020 at 02:31:55PM +0200, Etienne Carriere wrote: > On Thu, 8 Oct 2020 at 21:17, Sudeep Holla <sudeep.holla@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. >
Fair enough, but it also adds complexity. Do you have a master SCMI server implementation in that case. As some protocols like system might need to be broadcast to all servers and master server needs to take appropriate action.
> 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. >
OK, as Cristian has already mentioned we need to clean up a bit on these initcalls and Cristian has some WIP patches, I would like to wait and look at them instead of breaking other usecases with patch(multiple devices per protocol within one scmi server)
-- Regards, Sudeep
| |