Re: [GIT PULL 1/7] soc/tegra: Changes for v5.20-rc1

From: Jon Hunter <jonathanh@nvidia.com>
To: Thierry Reding <thierry.reding@gmail.com>, Arnd Bergmann <arnd@arndb.de>
Cc: arm-soc <arm@kernel.org>, SoC Team <soc@kernel.org>,
	"open list:TEGRA ARCHITECTURE SUPPORT"
	<linux-tegra@vger.kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	linux-edac@vger.kernel.org, Borislav Petkov <bp@alien8.de>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Tony Luck <tony.luck@intel.com>,
	James Morse <james.morse@arm.com>,
	Robert Richter <rric@kernel.org>
Subject: Re: [GIT PULL 1/7] soc/tegra: Changes for v5.20-rc1
Date: Thu, 14 Jul 2022 07:30:46 +0100	[thread overview]
Message-ID: <7620832b-9d76-175b-fe93-dc91cf3732c7@nvidia.com> (raw)
In-Reply-To: <Ys8phjCTfQTD41g+@orome>

On 13/07/2022 21:22, Thierry Reding wrote:

...

>>>>> Bitan Biswas (1):
>>>>>        soc/tegra: fuse: Expose Tegra production status
>>>>
>>>> Please don't just add random attributes in the soc device infrastructure.
>>>> This one has a completely generic name but a SoC specific
>>>> meaning, and it lacks a description in Documentation/ABI.
>>>> Not sure what the right ABI is here, but this is something that needs
>>>> to be discussed more broadly when you send a new version.
>>>
>>> I wasn't aware that the SoC device infrastructure was restricted to only
>>> standardized attributes. Looks like there are a few other outliers that
>>> add custom attributes: UX500, ARM Integrator and RealView, and OMAP2.
>>>
>>> Do we have some other place where this kind of thing can be exposed? Or
>>> do we just need to come up with some better way of namespacing these?
>>> Perhaps it would also be sufficient if all of these were better
>>> documented so that people know what to look for on their platform of
>>> interest.
>>
>> It's not a 100% strict rule, I've just tried to limit it as much as possible,
>> and sometimes missed drivers doing it anyway. My main goal here is
>> to make things consistent between SoC families, so if one piece of
>> information is provided by a number of them, I'd rather have a standard
>> attribute, or a common way of encoding this in the existing attributes
>> than to have too many custom attributes with similar names.
> 
> The major/minor attributes that we have on Tegra SoCs should be easy to
> standardize. It seems like those could be fairly common. The other one
> that we have is the "platform" one, which I suppose is not as easy to
> standardize. I don't recall the exact details, but I think we're mostly
> interested in whether or not the platform is simulation or silicon. The
> exact simulation value is not something that userspace scripts will look
> at, as far as I recall.
> 
> Jon, correct me if I'm wrong.

There are a few different simulation types and I am seen some userspace 
code convert the value and display the actual type. However, in reality 
I am not sure how much this is used, but yes at least identifying that 
this is silicon is used widely from what I have seen.

Jon

-- 
nvpublic

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel