path: root/Documentation/gpio.txt
diff options
authorDavid Brownell <david-b@pacbell.net>2007-07-19 08:47:52 (GMT)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-19 17:04:43 (GMT)
commita0a9983509f45b2225ca87fdcf7b40ea916834ed (patch)
treea70151c57f184bccd24175fa19a585021e297973 /Documentation/gpio.txt
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>
Diffstat (limited to 'Documentation/gpio.txt')
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt
index 36af58e..218a865 100644
--- a/Documentation/gpio.txt
+++ b/Documentation/gpio.txt
@@ -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

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