回复: 回复: 回复: [EXT] Re: [PATCH v3 02/17] firmware: scmi: smt: Interrupt communication enable

[Alice Guo (OSS)]

> -----邮件原件-----
> 发件人: Marek Vasut <marex at denx.de>
> 发送时间: 2025年1月7日 19:11
> 收件人: Alice Guo (OSS) <alice.guo at oss.nxp.com>; Tom Rini
> <trini at konsulko.com>; Stefano Babic <sbabic at denx.de>; Fabio Estevam
> <festevam at gmail.com>; dl-uboot-imx <uboot-imx at nxp.com>; Lukasz
> Majewski <lukma at denx.de>; Sean Anderson <seanga2 at gmail.com>; Simon
> Glass <sjg at chromium.org>; Alper Nebi Yasak <alpernebiyasak at gmail.com>
> 抄送: u-boot at lists.denx.de; tharvey at gateworks.com; Viorel Suman
> <viorel.suman at nxp.com>; Ye Li <ye.li at 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 at 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.