[patch 2.6.22] gpio calls don't need i/o barriers

From: David Brownell
Date: Tue Jul 10 2007 - 19:40:40 EST


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@xxxxxxxxxxxxxxxxxxxxx>
---
Documentation/gpio.txt | 3 +++
1 file changed, 3 insertions(+)

--- g26.orig/Documentation/gpio.txt 2007-06-24 13:23:21.000000000 -0700
+++ g26/Documentation/gpio.txt 2007-06-24 13:32:01.000000000 -0700
@@ -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
-----------------
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/