回复: 回复: [EXT] Re: [PATCH v4 10/20] scmi_protocols: update struct scmi_base_discover_list_protocols_out

[Alice Guo (OSS)]

> -----邮件原件-----
> 发件人: Marek Vasut <marex at denx.de>
> 发送时间: 2025年3月4日 4:19
> 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; Alice Guo
> <alice.guo at nxp.com>; Ye Li <ye.li at nxp.com>
> 主题: Re: 回复: [EXT] Re: [PATCH v4 10/20] scmi_protocols: update struct
> scmi_base_discover_list_protocols_out
> 
> On 3/3/25 11:37 AM, Alice Guo (OSS) wrote:
> 
> Hi,
> 
> >>> @protocols is an array of protocol identifiers that are implemented,
> >>> excluding the Base protocol. The number of elements of @protocols is
> >>> specified by callee-side. Currently, set it to 4 is enough for i.MX95.
> >> Can you please try something like this instead ? That should be
> >> future-proof:
> >>
> >> diff --git a/drivers/firmware/scmi/base.c
> >> b/drivers/firmware/scmi/base.c index f4e3974ff5b..92d278edfaf 100644
> >> --- a/drivers/firmware/scmi/base.c
> >> +++ b/drivers/firmware/scmi/base.c
> >> @@ -258,17 +258,16 @@ static int
> >> scmi_base_discover_impl_version_int(struct udevice *dev,
> >>    static int scmi_base_discover_list_protocols_int(struct udevice *dev,
> >>                                                   u8
> **protocols)
> >>    {
> >> -       struct scmi_base_discover_list_protocols_out out;
> >> +       struct scmi_base_discover_list_protocols_out *out;
> >>          int cur;
> >>          struct scmi_msg msg = {
> >>                  .protocol_id = SCMI_PROTOCOL_ID_BASE,
> >>                  .message_id =
> SCMI_BASE_DISCOVER_LIST_PROTOCOLS,
> >>                  .in_msg = (u8 *)&cur,
> >>                  .in_msg_sz = sizeof(cur),
> >> -               .out_msg = (u8 *)&out,
> >> -               .out_msg_sz = sizeof(out),
> >
> > The pointer and byte size of the buffer where the response message is stored
> should be provided before sending a BASE_DISCOVER_LIST PROTOCOLS
> message.
> >
> > There is a more reasonable way. Number of protocols that are implemented,
> excluding the Base protocol, can be obtained by sending a
> PROTOCOL_ATTRIBUTES message. But now this command is not supported in
> U-Boot. In this patch, ec8727b7e1 ("firmware: scmi: implement SCMI base
> protocol"), "u32 protocols[3];" is used. So, I think setting the array of packed
> SCMI protocol ID's to a fixed size is acceptable.
> NAK, let's not perpetuate this suboptimal implementation, please implement
> PROTOCOL_ATTRIBUTES if that's the way to find out the amount of supported
> protocols dynamically.

OK. Will do it according to your comment.