mtd/include/linux/mtd nand.h,1.72,1.73

[gleixner at infradead.org]

Update of /home/cvs/mtd/include/linux/mtd
In directory phoenix.infradead.org:/tmp/cvs-serv32473/include/linux/mtd

Modified Files:
	nand.h 
Log Message:
[MTD] NAND: Reorganize chip locking

The code was wrong in several aspects. The locking order was
inconsistent, the device aquire code did not reset a variable
after a wakeup and the wakeup handling was not working for
applications where multiple chips are sharing a single
hardware controller.
When a hardware controller is available the locking is now
reduced to the hardware controller lock and the waitqueue is
moved to the hardware controller structure in order to avoid
a wake_up_all().

The problem was pointed out by Ben Dooks, who also found the
missing variable reset as main cause for his deadlock problem.



Index: nand.h
===================================================================
RCS file: /home/cvs/mtd/include/linux/mtd/nand.h,v
retrieving revision 1.72
retrieving revision 1.73
diff -u -r1.72 -r1.73
--- nand.h	27 May 2005 08:31:33 -0000	1.72
+++ nand.h	31 May 2005 19:39:17 -0000	1.73
@@ -253,10 +253,13 @@
  * struct nand_hw_control - Control structure for hardware controller (e.g ECC generator) shared among independend devices
  * @lock:               protection lock  
  * @active:		the mtd device which holds the controller currently
+ * @wq:			wait queue to sleep on if a NAND operation is in progress
+ *                      used instead of the per chip wait queue when a hw controller is available
  */
 struct nand_hw_control {
 	spinlock_t	 lock;
 	struct nand_chip *active;
+	wait_queue_head_t wq;
 };
 
 /**