> -----Original Message----- > From: Jassi Brar [mailto:jassisinghbrar@xxxxxxxxx] > On Tue, Aug 21, 2018 at 8:30 AM A.s. Dong <aisheng.dong@xxxxxxx> wrote: > > > > > > + > > > > +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. > > > 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
