On 23/11/2022 11:19, neil.armstrong@xxxxxxxxxx wrote: >>>> We have already three of such "memory region devices" and we keep >>>> growing it. It's not scalable. >>> >>> If we want to properly describe this, we must then represent the MPSS subsystem >>> and associate this memory region. >> >> I don't see why. None of devices in your DTS reference this memory >> region, so it is purely to keep it mapped for Modem, right? In such case >> I still do not get why PAS/PIL, who starts and stops the remote >> processor, could not prepare the memory and share it with modem. > > OK you've got a point, but this is still an implementation detail. > > I got some more background about why this memory zone appeared, before it > was including in the modem reserved-memories, but for flexibility reasons > this is now in the hands of the APPS runtime (linux) to setup this memory > zone and share it to the MPSS subsystem. > > So the only requirement for the PAS is to make sure this zone is shared > before starting the startup process, not to actually do the share setup. > > The zone will need to be shared whatever the PAS state is (probe, startup, remove, ...). I don't understand here. The memory region should be shared before remote processor start or before the PAS probe? If the second, why? What if your driver probes a bit later - after PAS probe? Then all is lost... Best regards, Krzysztof
