Commit a0a99835 authored Jul 19, 2007 by David Brownell Committed by Linus Torvalds Jul 19, 2007

gpio calls don't need i/o barriers

Clarify that drivers using the GPIO operations don't need to issue io
barrier instructions themselves. Previously this wasn't clear, and at
least one platform assumed otherwise (and would thus break various
otherwise-portable drivers which don't issue barriers).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e53252d9

Documentation/gpio.txt

+3 −0

Original line number	Diff line number	Diff line
		@@ -75,6 +75,9 @@ using the include file:
		If you stick to this convention then it'll be easier for other developers to
		see what your code is doing, and help maintain it.

		Note that these operations include I/O barriers on platforms which need to
		use them; drivers don't need to add them explicitly.


		Identifying GPIOs
		-----------------