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authorDavid Brownell <david-b@pacbell.net>2007-07-19 04:47:52 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-19 13:04:43 -0400
commita0a9983509f45b2225ca87fdcf7b40ea916834ed (patch)
treea70151c57f184bccd24175fa19a585021e297973
parente53252d97e670a38b1d2e9723b48077bba11ddda (diff)
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>
-rw-r--r--Documentation/gpio.txt3
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt
index 36af58eba136..218a8650f48d 100644
--- a/Documentation/gpio.txt
+++ b/Documentation/gpio.txt
@@ -75,6 +75,9 @@ using the include file:
75If you stick to this convention then it'll be easier for other developers to 75If you stick to this convention then it'll be easier for other developers to
76see what your code is doing, and help maintain it. 76see what your code is doing, and help maintain it.
77 77
78Note that these operations include I/O barriers on platforms which need to
79use them; drivers don't need to add them explicitly.
80
78 81
79Identifying GPIOs 82Identifying GPIOs
80----------------- 83-----------------