ARM: 6940/1: fiq: Briefly document driver responsibilities for suspend/resume
authorDave Martin <dave.martin@linaro.org>
Tue, 24 May 2011 11:11:48 +0000 (12:11 +0100)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Thu, 26 May 2011 09:31:06 +0000 (10:31 +0100)
commit2846d84ffa4408c9810fabad74cb7aec410352fc
tree25e0a37c87f283e24808ecceb84bb846f9e49e07
parentdc2eb928a1bcf6a48f40c1f2ff21b66bdbf91a3c
ARM: 6940/1: fiq: Briefly document driver responsibilities for suspend/resume

Drivers which make use of the FIQ interrupt may require the state
of the FIQ mode registers to be preserved across suspend/resume.

Because the FIQ mode registers are not saved and restored
automatically by the kernel, driver authors will need to do the
appropriate save/restore in their own driver suspend/resume
handlers.

Implementing global automatic save/restore of the FIQ state does
not appear appropriate, since this by itself is not sufficient for
FIQ-based drivers to function correctly across suspend/resume in
any case.

This patch adds a brief explanatory note to fiq.h documenting the
requirement placed on driver authors.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/include/asm/fiq.h