Re: [PATCH v5 02/13] dt-bindings: remoteproc: qcom: pas: Add QMP property

Quoting Sibi Sankar (2021-08-20 07:24:02)

On 2021-08-20 00:25, Stephen Boyd wrote:

quoted

Quoting Sibi Sankar (2021-08-18 20:02:05)

quoted

The load state power-domain, used by the co-processors to notify the
Always on Subsystem (AOSS) that a particular co-processor is up/down,
suffers from the side-effect of changing states during suspend/resume.
However the co-processors enter low-power modes independent to that of
the application processor and their states are expected to remain
unaltered across system suspend/resume cycles. To achieve this
behavior
let's drop the load state power-domain and replace them with the qmp
property for all SoCs supporting low power mode signalling.

How do we drop the load state property without breaking existing DTBs?
Maybe we need to leave it there and then somehow make it optional? Or
do
we not care about this problem as the driver will start ignoring it?

We can afford to break the bindings
because of the following reason:

* Load state in mainline is currently
   broken i.e. it doesn't serve its
   main purpose of signalling AOP of
   the correct state of Q6 during
   system suspend/resume. Thus we
   can maintain current functionality
   even without the load state votes
   i.e. when a new kernel with load
   state removed is used with an older
   dtb the remoteproc functionality
   will remain the same.

Alright. Is that reflected somewhere in the commit text? I must have
missed it. Can you please add it?