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Date: Mon, 3 Jun 2024 14:46:30 +0200
From: Andrew Lunn <andrew@lunn.ch>
To: Benjamin Schneider <bschnei@gmail.com>
Cc: Gregory Clement <gregory.clement@bootlin.com>,
	Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
	linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
	Benjamin Schneider <ben@bens.haus>
Subject: Re: [PATCH] cpufreq: enable 1200Mhz clock speed for armada-37xx
Message-ID: <f2284d6b-2e75-4896-9e10-caf2f72854a0@lunn.ch>
References: <20240603012804.122215-1-ben@bens.haus>
 <20240603012804.122215-2-ben@bens.haus>
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On Sun, Jun 02, 2024 at 06:26:38PM -0700, Benjamin Schneider wrote:
> This frequency was disabled because of unresolved stability problems.
> However, based on several months of testing, the source of the
> stability problems seems to be the bootloader, not the kernel.
> Marvell has recently merged changes to their bootloader source that
> addresses the stability issues when frequency scaling is enabled at
> all frequencies including 1.2Ghz.

The problem is, most systems don't have the new bootloader. And so if
you enable 1.2GHz, they are going to be unstable.

Rather than making this unconditional, i think it needs to be
conditional on knowing the bootloader has been upgraded. Could you add
code which looks in the DDRPHY and see if 0xC0001004 has the correct
value. Only then enable the additional clock speed.

	Andrew