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Date: Mon, 18 Mar 2024 11:08:58 -0400
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Subject: Re: [PATCH 2/2] nvmem: Remove qoriq-efuse in favor of layerscape-sfp
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To: richard@bit42.se
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
 linux-kernel@vger.kernel.org,
 =?UTF-8?Q?Niklas_S=C3=B6derlund?= <niklas.soderlund@ragnatech.se>,
 Michael Walle <michael@walle.cc>,
 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
References: <20240316002026.1808336-1-sean.anderson@linux.dev>
 <20240316002026.1808336-2-sean.anderson@linux.dev>
 <6f5636e65df5616395cc8e24f63b09ef@bit42.se>
From: Sean Anderson <sean.anderson@linux.dev>
In-Reply-To: <6f5636e65df5616395cc8e24f63b09ef@bit42.se>
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On 3/18/24 04:32, richard@bit42.se wrote:
> On 2024-03-16 01:20, Sean Anderson wrote:
>> The qoriq-efuse driver is a duplicate of layerscape-sfp.c. The T-series
>> uses TA 2.0, while Layerscape uses TA 2.1 or 3.0 (depending on the
>> chip). Add appropriate compatibles to the layerscape-sfp driver and
>> remove the qoriq-efuse driver. I did not add support for P-series SoCs,
>> since they use TA 1.0 which doesn't share a major version with either of
>> the existing implementations.
>>
>> The qoriq-efuse driver does not properly abstract the location/offset of
>> the fuses properly, instead exposing the device's whole address range to
>> userspace. This is not appropriate, as the fuses only occupy a small
>> portion of this range. The layerscape-sfp module correctly constrains
>> the nvmem size to the fuses size. This represents a (necessary)
>> compatibility break. The qoriq-efuse driver has been in-tree for around
>> six months. Hopefully this will limit the fallout.
>>
>> I would appreciate if someone with access to trust architecture 2.0 user
>> guide could confirm the number of fuses.
>>
>> Fixes: 0861110bb421 ("nvmem: add new NXP QorIQ eFuse driver")
>> Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
> I don't think Fixes is appropriate here. Apart from that:

As mentioned in the second paragraph, the original driver exposes the whole
register space in the nvmem. I consider this a bug.

--Sean

> Acked-by: Richard Alpe <richard@bit42.se>