Subject: Re: 回复: 回复: 回复: [EXT] Re: [PATCH v3 02/17] firmware: scmi: smt: Interrupt communication enable
On 1/8/25 3:55 AM, Alice Guo (OSS) wrote:
-----邮件原件----- 发件人: Marek Vasut marex@denx.de 发送时间: 2025年1月7日 19:11 收件人: Alice Guo (OSS) alice.guo@oss.nxp.com; Tom Rini trini@konsulko.com; Stefano Babic sbabic@denx.de; Fabio
Estevam
festevam@gmail.com; dl-uboot-imx uboot-imx@nxp.com;
Lukasz
Majewski lukma@denx.de; Sean Anderson
seanga2@gmail.com; Simon
Glass sjg@chromium.org; Alper Nebi Yasak
抄送: u-boot@lists.denx.de; tharvey@gateworks.com; Viorel Suman viorel.suman@nxp.com; Ye Li ye.li@nxp.com 主题: Re: 回复: 回复: [EXT] Re: [PATCH v3 02/17] firmware: scmi:
smt:
Interrupt communication enable
On 1/7/25 4:24 AM, Alice Guo (OSS) wrote:
主题: Re: 回复: [EXT] Re: [PATCH v3 02/17] firmware: scmi: smt: Interrupt communication enable
On 1/6/25 7:17 AM, Alice Guo (OSS) wrote:
> On 1/3/25 7:45 AM, Alice Guo wrote: >> From: Viorel Suman viorel.suman@nxp.com >> >> When interrupt driven communication is supported > > U-Boot does not use interrupts. > >> , the transport allows >> the caller to choose between interrupt and polling driven >> communications. To make the choice, the channel flags are
used.
>> i.MX95 uses interrupt driven communication so that Channel
flags
>> should be set to 1. > > How does this work in U-Boot, which does not use interrupts ?
Hi Marek,
The clearer explanation will be added in the commit log.
This is based on Arm® System Control and Management
Interface
Platform
Design Document Version 3.2 (Document number: DEN0056E)
5.1.2. When
Bit[0] of Channel flags is 1, the System Manager runs on M core will trigger general-purpose interrupts to A core. U-Boot polls General-purpose Status (GSR) until GIPn is set. If U-Boot does polling, why does this bit need to be set, shouldn't the bit be cleared instead ?
My commit log may have caused your misunderstanding. If the bit
is
not set,
the System Manager will not request doorbell interrupt. The
following
is the code from imx-sm:
if (callee) { /* Generate completion interrupt */ if ((buf->channelFlags & SMT_COMP_INT) != 0U) { status = RPC_SMT_DoorbellRing(smtChannel); } }Can the SM be updated instead ?
System Manager not only interacts with U-Boot, but also with
Linux/QNX/RTOS. System Manager cannot be changed. How come other SCMI providers (like optee) do not need this kind of change ?
Could we use a Kconfig option here, saying CONFIG_SCMI_INTR_EN? Then to i.MX95, select this Kconfig option and not break others saying optee.
There is less chance for System Manager to change. If you would like to do some change, you could do a PR, I could ask owner to give a look.
Thanks, Peng.