[PATCH] mtd: atmel_nand: fix bug driver will in a dead lock if no nand detected

Josh Wu josh.wu at atmel.com
Tue Nov 5 04:59:07 EST 2013


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().

Signed-off-by: Josh Wu <josh.wu at atmel.com>
---
 drivers/mtd/nand/atmel_nand.c |    1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index ef9c9f5..469d4e2 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -2142,7 +2142,6 @@ 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;
 }
 
-- 
1.7.9.5




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