-----Original Message-----
From: Jassi Brar [mailto:jassisinghbrar at gmail.com]
On Tue, Aug 21, 2018 at 8:30 AM A.s. Dong [off-list ref] wrote:

quoted

quoted

quoted

+
+The System Controller Firmware (SCFW) is a low-level system
+function which runs on a dedicated Cortex-M core to provide
+power, clock, and resource management. It exists on some i.MX8
+processors. e.g. i.MX8QM (QM, QP), and i.MX8QX (QXP, DX).
+
+The AP communicates with the SC using a multi-ported MU module
+found in the LSIO subsystem. The current definition of this MU
+module provides
+5 remote AP connections to the SC to support up to 5 execution
+environments (TZ, HV, standard Linux, etc.). The SC side of this
+MU module interfaces with the LSIO DSC IP bus. The SC firmware
+will communicate with this MU using the MSI bus.

How are 5 users supported with only 4 channels defined below?

There're 5 MU instances designed to be specifically communicate with
SCU Firmware on MX8 hardware.

This is correct.

quoted

With the new generic mu binding [1], each MU instance is abstracted
Into 16 virtual MU channels. (4 Tx, 4 Rx, 4 Tx doorbell, 4 Rx doorbell).
(MU has 4 pair of Tx/Rx data register which can be used to
send/receive multi words. With new binding, each data register is
abstracted into one MU channel, totally 8 channels for data transfer).

SCU protocol is already designed to uses all data registers to
send/receive multi words according to MU hardware reference manual. So
it must use all channels in one MU instances with new binding.

FYI, this is incorrect.
The 16 channels are physical and not virtual. In fact, all this is to avoid virtual
channels.
The physical resources required by new bindings are exactly the same as by old
bindings. Now you use 8 physical channels instead of 1 virtual.

Okay, got it.
I'm fine to refer to them all as physical channels.
Thanks

Regards
Dong Aisheng