3.12-stable review patch. If anyone has any objections, please let me know.
------------------
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;
}
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