From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] mach-ixp4xx: made gpio functions atomic
Date: Sun, 30 Oct 2011 18:52:08 +0000 [thread overview]
Message-ID: <20111030185208.GD19187@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <1319973693-19063-1-git-send-email-fransmeulenbroeks@gmail.com>
On Sun, Oct 30, 2011 at 12:21:33PM +0100, Frans Meulenbroeks wrote:
> gpio_line_set and gpio_line config on ixp4xx were not atomic
> This patch fixes this by surrounding them with local_irq_save and
> local_irq_restore calls, similar to the way Lennert Buytenhek
> implemented this for iop. (see arch/arm/plat-iop/gpio.c)
>
> Signed-off-by: Frans Meulenbroeks <fransmeulenbroeks@gmail.com>
> ---
>
> Note: an alternative solution would be to use the set_bit and
> clear_bit atomic functions, but I felt it better to do things
> the same way as Lennert did. Also it could be that this is a few
> bytes smaller. Didn't check that.
set_bit and clear_bit should not be used on IO memory - on ARMv6 and
later these use the load exclusive/store exclusive operations which
are only valid on 'normal memory' mappings and not 'device' mappings.
Plus of course, IO memory is supposed to be __iomem and accessed using
the proper accessors, and using set_bit and clear_bit on such pointers
will issue sparse warnings.
next prev parent reply other threads:[~2011-10-30 18:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-30 11:21 [PATCH] mach-ixp4xx: made gpio functions atomic Frans Meulenbroeks
2011-10-30 18:52 ` Russell King - ARM Linux [this message]
[not found] ` <CACW_hTY_CCSMWK1tYK_or5g5-2NQUbfLiJxLhKvT=V8BPuODMg@mail.gmail.com>
2011-10-31 11:06 ` Russell King - ARM Linux
[not found] ` <CACW_hTYn1_9fDCve2gg0Wr-DkNqWfaEQXTtT+ooFsBBo9ksivw@mail.gmail.com>
2012-01-03 9:11 ` Russell King - ARM Linux
-- strict thread matches above, loose matches on Subject: below --
2011-08-11 18:39 Frans Meulenbroeks
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