linux-kernel - Re: [PATCH v2 05/21] ARM: tegra: clock: Disable clocks left on by bootloader

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Date:	Sun, 20 Feb 2011 16:40:51 -0800
From:	Olof Johansson <olof@...om.net>
To:	Colin Cross <ccross@...roid.com>
Cc:	linux-tegra@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	konkers@...roid.com, Russell King <linux@....linux.org.uk>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 05/21] ARM: tegra: clock: Disable clocks left on by bootloader

Hi,

On Sat, Feb 19, 2011 at 2:25 PM, Colin Cross <ccross@...roid.com> wrote:
> Adds CONFIG_TEGRA_DISABLE_BOOTLOADER_CLOCKS that iterates
> through all clocks, disabling any for which the refcount
> is 0 but the clock init detected the bootloader left the
> clock on.

I would argue that any kernel functionality that relies on clocks
being left on my bootloader is buggy, and/or should at least have
those clocks enabled in the static clock tables for the boards in
question, since it creates an undocumented dependency on firmware.

I would prefer if it disabled the clocks by default (after warning),
but that there was a runtime way to override while debugging (i.e. add
a bootarg 'keep_fwclocks' or similar to keep the firmware-enabled
clocks running and just warn about them).

-Olof
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