This is a note to let you know that I've just added the patch titled
mfd: kempld-core: Fix potential hang-up during boot
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mfd-kempld-core-fix-potential-hang-up-during-boot.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 204747c970c0d568721c76ab8a57dde0e5dcf0d5 Mon Sep 17 00:00:00 2001
From: Guenter Roeck <linux@xxxxxxxxxxxx>
Date: Thu, 20 Mar 2014 08:12:28 -0700
Subject: mfd: kempld-core: Fix potential hang-up during boot
From: Guenter Roeck <linux@xxxxxxxxxxxx>
commit 204747c970c0d568721c76ab8a57dde0e5dcf0d5 upstream.
On PXT and COMe-cPC2 boards it is observed that the hardware
mutex is acquired but not being released during initialization.
This can result in a hang-up during boot if the driver is built
into the kernel.
Releasing the mutex twice if it was acquired fixes the problem.
Subsequent request/release cycles work as expected, so the fix is
only needed during initialization.
Reviewed-by: Michael Brunner <michael.brunner@xxxxxxxxxxx>
Tested-by: Michael Brunner <michael.brunner@xxxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mfd/kempld-core.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/drivers/mfd/kempld-core.c
+++ b/drivers/mfd/kempld-core.c
@@ -322,9 +322,12 @@ static int kempld_detect_device(struct k
return -ENODEV;
}
- /* Release hardware mutex if aquired */
- if (!(index_reg & KEMPLD_MUTEX_KEY))
+ /* Release hardware mutex if acquired */
+ if (!(index_reg & KEMPLD_MUTEX_KEY)) {
iowrite8(KEMPLD_MUTEX_KEY, pld->io_index);
+ /* PXT and COMe-cPC2 boards may require a second release */
+ iowrite8(KEMPLD_MUTEX_KEY, pld->io_index);
+ }
mutex_unlock(&pld->lock);
Patches currently in stable-queue which might be from linux@xxxxxxxxxxxx are
queue-3.14/mfd-kempld-core-fix-potential-hang-up-during-boot.patch
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