This is a note to let you know that I've just added the patch titled
mtd: atmel_nand: fix bug driver will in a dead lock if no nand detected
to the 3.12-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:
mtd-atmel_nand-fix-bug-driver-will-in-a-dead-lock-if-no-nand-detected.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a749d13acd8e079ed4c77a9456d842dc94af8f17 Mon Sep 17 00:00:00 2001
From: Josh Wu <josh.wu@xxxxxxxxx>
Date: Tue, 5 Nov 2013 17:59:07 +0800
Subject: mtd: atmel_nand: fix bug driver will in a dead lock if no nand detected
From: Josh Wu <josh.wu@xxxxxxxxx>
commit a749d13acd8e079ed4c77a9456d842dc94af8f17 upstream.
In the atmel driver probe function, the code shows like following:
atmel_nand_probe(...) {
...
err_nand_ioremap:
platform_driver_unregister(&atmel_nand_nfc_driver);
return res;
}
If no nand flash detected, the driver probe function will goto
err_nand_ioremap label.
Then platform_driver_unregister() will be called. It will get the
lock of atmel_nand device since it is parent of nfc_device. The
problem is the lock is already hold by atmel_nand_probe itself.
So system will be in a dead lock.
This patch just simply removed to platform_driver_unregister() call.
When atmel_nand driver is quit the platform_driver_unregister() will
be called in atmel_nand_remove().
[Brian: the NAND platform probe really has no business
registering/unregistering another driver; this fixes the deadlock, but
we should follow up the likely racy behavior here with a better
architecture]
Signed-off-by: Josh Wu <josh.wu@xxxxxxxxx>
Signed-off-by: Brian Norris <computersforpeace@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mtd/nand/atmel_nand.c | 1 -
1 file changed, 1 deletion(-)
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -2177,7 +2177,6 @@ err_no_card:
if (host->dma_chan)
dma_release_channel(host->dma_chan);
err_nand_ioremap:
- platform_driver_unregister(&atmel_nand_nfc_driver);
return res;
}
Patches currently in stable-queue which might be from josh.wu@xxxxxxxxx are
queue-3.12/mtd-atmel_nand-fix-bug-driver-will-in-a-dead-lock-if-no-nand-detected.patch
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