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Commit fb6d080c authored by Alexey Korolev's avatar Alexey Korolev Committed by Linus Torvalds
Browse files

mtd: fix broken state in CFI driver caused by FL_SHUTDOWN 



THe CFI driver in 2.6.24 kernel is broken.  Not so intensive read/write
operations cause incomplete writes which lead to kernel panics in JFFS2.

We investigated the issue - it is caused by bug in FL_SHUTDOWN parsing code.
Sometimes chip returns -EIO as if it is in FL_SHUTDOWN state when it should
wait in FL_PONT (error in order of conditions).

The following patch fixes the bug in state parsing code of CFI.  Also I've
added comments to notify developers if they want to add new case in future.

Signed-off-by: default avatarAlexey Korolev <akorolev@infradead.org>
Reviewed-by: default avatarJoern Engel <joern@logfs.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4077960e

drivers/mtd/chips/cfi_cmdset_0001.c

+5 −5
Original line number Original line Diff line number Diff line
@@ -718,7 +718,7 @@ static int chip_ready (struct map_info *map, struct flchip *chip, unsigned long 
			/* Someone else might have been playing with it. */

			/* Someone else might have been playing with it. */

			return -EAGAIN;

			return -EAGAIN;

		}

		}



		/* Fall through */

	case FL_READY:

	case FL_READY:

	case FL_CFI_QUERY:

	case FL_CFI_QUERY:

	case FL_JEDEC_QUERY:

	case FL_JEDEC_QUERY:
@@ -778,14 +778,14 @@ static int chip_ready (struct map_info *map, struct flchip *chip, unsigned long 
		chip->state = FL_READY;

		chip->state = FL_READY;

		return 0;

		return 0;





	case FL_SHUTDOWN:

		/* The machine is rebooting now,so no one can get chip anymore */

		return -EIO;

	case FL_POINT:

	case FL_POINT:

		/* Only if there's no operation suspended... */

		/* Only if there's no operation suspended... */

		if (mode == FL_READY && chip->oldstate == FL_READY)

		if (mode == FL_READY && chip->oldstate == FL_READY)

			return 0;

			return 0;



		/* Fall through */

	case FL_SHUTDOWN:

		/* The machine is rebooting now,so no one can get chip anymore */

		return -EIO;

	default:

	default:

	sleep:

	sleep:

		set_current_state(TASK_UNINTERRUPTIBLE);

		set_current_state(TASK_UNINTERRUPTIBLE);