[PATCH/RFC,120/390] pinctrl: implement pinctrl deferred probing

Commit Message

Simon Horman March 29, 2013, 2:40 a.m. UTC

From: Linus Walleij <[e-mail]>

If drivers try to obtain pinctrl handles for a pin controller that
has not yet registered to the subsystem, we need to be able to
back out and retry with deferred probing. So let's return
-EPROBE_DEFER whenever this location fails. Also downgrade the
errors to info, maybe we will even set them to debug once the
deferred probing is commonplace.

Cc: Arnd Bergmann <[e-mail]>
Reviewed-by: Mark Brown <[e-mail]>
Acked-by: Stephen Warren <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>
(cherry picked from commit c05127c4e2c6e7d9949347a76fd05c337bcd5e84)

Signed-off-by: Simon Horman <[e-mail]>
---
 Documentation/pinctrl.txt |    5 +++++
 1 file changed, 5 insertions(+)

Patch

diff --git a/Documentation/pinctrl.txt b/Documentation/pinctrl.txt
index e40f4b4..f46b5b4 100644
--- a/Documentation/pinctrl.txt
+++ b/Documentation/pinctrl.txt
@@ -1057,6 +1057,11 @@  requested pinctrl handles, for example if the pinctrl driver has not yet
 registered. Thus make sure that the error path in your driver gracefully
 cleans up and is ready to retry the probing later in the startup process.
 
+NOTE: the pinctrl system will return -EPROBE_DEFER if it cannot find the
+requested pinctrl handles, for example if the pinctrl driver has not yet
+registered. Thus make sure that the error path in your driver gracefully
+cleans up and is ready to retry the probing later in the startup process.
+
 
 System pin control hogging
 ==========================