[3.5.y.z extended stable] Patch "misc: atmel_pwm: add deferred-probing support" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Thu Dec 5 10:29:35 UTC 2013


This is a note to let you know that I have just added a patch titled

    misc: atmel_pwm: add deferred-probing support

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From bdb57c3029b80da8e0ca83d4501e60dd99ebb535 Mon Sep 17 00:00:00 2001
From: Johan Hovold <jhovold at gmail.com>
Date: Tue, 22 Oct 2013 18:32:39 +0200
Subject: misc: atmel_pwm: add deferred-probing support

commit 5c6d6fd1564138ad048564e48639f842714a90c6 upstream.

Two drivers (atmel-pwm-bl and leds-atmel-pwm) currently depend on the
atmel_pwm driver to have bound to any pwm-device before their devices
are probed.

Support deferred probing of such devices by making sure to return
-EPROBE_DEFER from pwm_channel_alloc when no pwm-device has yet been
bound.

Signed-off-by: Johan Hovold <jhovold at gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/misc/atmel_pwm.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/atmel_pwm.c b/drivers/misc/atmel_pwm.c
index 28f5aaa..2741108 100644
--- a/drivers/misc/atmel_pwm.c
+++ b/drivers/misc/atmel_pwm.c
@@ -90,8 +90,10 @@ int pwm_channel_alloc(int index, struct pwm_channel *ch)
 	unsigned long	flags;
 	int		status = 0;

-	/* insist on PWM init, with this signal pinned out */
-	if (!pwm || !(pwm->mask & 1 << index))
+	if (!pwm)
+		return -EPROBE_DEFER;
+
+	if (!(pwm->mask & 1 << index))
 		return -ENODEV;

 	if (index < 0 || index >= PWM_NCHAN || !ch)
--
1.8.3.2





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