From: Jeremy Kerr <jk@codeconstruct.com.au>
To: Adam Young <admiyo@amperemail.onmicrosoft.com>,
admiyo@os.amperecomputing.com,
Matt Johnston <matt@codeconstruct.com.au>,
Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Sudeep Holla <sudeep.holla@arm.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Huisong Li <lihuisong@huawei.com>
Subject: Re: [PATCH v24 1/1] mctp pcc: Implement MCTP over PCC Transport
Date: Mon, 18 Aug 2025 08:33:48 +0800 [thread overview]
Message-ID: <d6b7d0c82806ef41bc7ee7173595d334acbf3b17.camel@codeconstruct.com.au> (raw)
In-Reply-To: <5a061bbd-637b-41c1-a6a7-5a14e479e572@amperemail.onmicrosoft.com>
Hi Adam,
> > And just confirming: the pcc header format is now all host-endian - or
> > is that a firmware-specified endianness? (what happens if the OS may
> > boot in either BE or LE? is that at all possible for any PCC-capable
> > hardware, or are we otherwise guaranteed that we're the same endianness
> > as the consumer?)
>
> The specification does not specify endianess. It is not addressed in
> the ACPI PCC spec nor the MCTP over PCC spec. There does not seem to
> be any endianess modifiers in any of the ACPI code base.
There are a few cases of endian conversion, they appear to be cases
where a pre-defined data format is used, and only where that data is BE.
That's a pretty strong indication that we don't need to worry about host
endian != firmware endian (I'm assuming that firmware is the entity
that parses the PCC headers you're constructing). All sounds good then.
Cheers,
Jeremy
next prev parent reply other threads:[~2025-08-18 0:33 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-11 15:38 [PATCH v24 0/1] MCTP Over PCC Transport admiyo
2025-08-11 15:38 ` [PATCH v24 1/1] mctp pcc: Implement MCTP over " admiyo
2025-08-13 4:46 ` Jeremy Kerr
2025-08-14 17:56 ` Adam Young
2025-08-18 0:33 ` Jeremy Kerr [this message]
2025-08-15 22:27 ` Adam Young
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