Thanks Dan and Sudeep,
On Thu, Dec 5, 2019 at 5:08 PM Sudeep Holla sudeep.holla@arm.com wrote:
On Tue, Dec 3, 2019 at 4:58 PM Sandeep Tripathy via TF-A tf-a@lists.trustedfirmware.org wrote:
Hi, system shutdown or system reset PSCI calls are invoked by the last core in the system. PSCI lib does not do cache flush for the last core /cluster and does not follow the core / cluster power down sequence. This may cause issue in a system if the system is not standalone one ie if the system is a slave or node in a bigger system with other coherent masters/PEs.
I am not sure if system off/reset is the right API to call in such a setup.
Please suggest if the PSCI spec expected 'shutdown/reset/reset2' to deliberately skip the core/cluster shutdown sequence.
Yes and IIRC this has been discussed in the past[1]. I expect to get some closure on open question on that thread. Quite a few questions were raised by few people and I am not sure if all were answered. I need to dig but but AFAIK it wasn't all answered.
I understood the concern of increase in reboot time for 'many-core' system and also agree what Dan mentioned as inherently racy situation to handle it perfectly for multi core. I did check the thread[1] and agree with plat-specific embedded hacks which does the job.
My query is more on the spec. The OS (eg: linux) and atf and psci spec seem to have assumed that it is managing an independent system or managing 'all' the masters in a coherent domain. What other reason could possibly encourage to not to follow a shutdown sequence.
-- Regards, Sudeep