tree 7cf9e67f6acec67b7e9d84768c8fc8821f636162
parent d8cb70d10a2d4e6b083b89044a68d860d0bf1eec
author Russell King <rmk@dyn-67.arm.linux.org.uk> 1193479295 +0100
committer Russell King <rmk+kernel@arm.linux.org.uk> 1193844100 +0000

[ARM] Fix FIQ issue with ARM926

Jon Eibertzon writes:
> We have noticed that the I-cache is disabled while waiting for
> interrupt in cpu_arm926_do_idle in arch/arm/mm/proc-arm926.S
> and we are curious to know why, because this causes us a great
> performance hit when executing in FIQ-handlers. Is it assumed
> here that every individual FIQ-handler re-enables the I-cache?

The I-cache disable is an errata workaround, so the solution is to
disable FIQs across the section with the I-cache disabled.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>