Re: [PATCH 3/3] arm64: Add KRYO4XX silver CPU cores to erratum list 1530923 and 1024718

From: Will Deacon <will@kernel.org>
To: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Marc Zyngier <maz@kernel.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Douglas Anderson <dianders@chromium.org>,
	Stephen Boyd <swboyd@chromium.org>,
	Andre Przywara <andre.przywara@arm.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-arm-msm@vger.kernel.org,
	Jeffrey Hugo <jhugo@codeaurora.org>
Subject: Re: [PATCH 3/3] arm64: Add KRYO4XX silver CPU cores to erratum list 1530923 and 1024718
Date: Fri, 3 Jul 2020 16:38:24 +0100	[thread overview]
Message-ID: <20200703153824.GA19327@willie-the-truck> (raw)
In-Reply-To: <7335e7fa1303a56a5e60339ed0c5d619@codeaurora.org>

On Fri, Jul 03, 2020 at 08:04:04PM +0530, Sai Prakash Ranjan wrote:
> On 2020-07-03 19:25, Will Deacon wrote:
> > On Tue, Jun 30, 2020 at 11:30:55PM +0530, Sai Prakash Ranjan wrote:
> > > KRYO4XX silver/LITTLE CPU cores with revision r1p0 are affected by
> > > erratum 1530923 and 1024718, so add them to the respective list.
> > > The variant and revision bits are implementation defined and are
> > > different from the their Cortex CPU counterparts on which they are
> > > based on, i.e., r1p0 is equivalent to rdpe.
> > 
> > So just to confirm, revisions prior to rdpe are unaffected, or do those
> > parts simply not exist?
> > 
> 
> There is one revision prior to this r0p1(r7pc) which has a different part
> number and are used in v1 of SoCs which are limited to only internal test
> platforms in the early stages of bringup and not used in actual devices out
> there, so I did not add it to the list but they are affected. Plus we would
> need to add another MIDR_QCOM_KRYO_4XX_SILVER_V1 if we are supporting them
> which I thought was not worth it when devices with those CPUs are not
> available.

Thanks, just wanted to make sure. Sounds like we can safely assume those
parts don't exist.

Will