[MTD] [NOR] Prevent erase command invocation on suspended chip

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=6c24e4161e80a5c03e9d969b5db73d8553846037
Commit:     6c24e4161e80a5c03e9d969b5db73d8553846037
Parent:     5f4d47d5d1060a93be83e33a167a53a7f8c08b20
Author:     Alexander Belyakov <abelyako at googlemail.com>
AuthorDate: Wed Nov 7 11:58:07 2007 +0300
Committer:  David Woodhouse <dwmw2 at infradead.org>
CommitDate: Mon Nov 26 15:54:16 2007 +0000

    [MTD] [NOR] Prevent erase command invocation on suspended chip
    
    while running stress tests we have met cfi_cmdset_0001.c driver issue.
    Working on multipartitional devices with erase suspend on write
    feature enabled it is possible to get erase operation invoked on chip
    with suspended erase. get_chip() looses information about earlier
    suspended erase and new erase operation gets issued. New erase
    operations report successful completion, but blocks remain dirty
    causing, for example, JFFS2 error messages like:
    
    ...
    Newly-erased block contained word 0x20031985 at offset 0x00200000
    Newly-erased block contained word 0x20031985 at offset 0x00280000
    Newly-erased block contained word 0x20031985 at offset 0x00240000
    ...
    
    The patch below fixes that issue.
    
    Signed-off-by: Alexander Belyakov <alexander.belyakov at intel.com>
    Acked-by: Nicolas Pitre <nico at cam.org>
    Signed-off-by: David Woodhouse <dwmw2 at infradead.org>
---
 drivers/mtd/chips/cfi_cmdset_0001.c |   15 +++++++++++++++
 1 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index ed5ce41..350671e 100644
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -795,6 +795,7 @@ static int chip_ready (struct map_info *map, struct flchip *chip, unsigned long
 static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr, int mode)
 {
 	int ret;
+	DECLARE_WAITQUEUE(wait, current);
 
  retry:
 	if (chip->priv && (mode == FL_WRITING || mode == FL_ERASING
@@ -851,6 +852,20 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr
 			spin_unlock(contender->mutex);
 		}
 
+		/* Check if we already have suspended erase
+		 * on this chip. Sleep. */
+		if (mode == FL_ERASING && shared->erasing
+		    && shared->erasing->oldstate == FL_ERASING) {
+			spin_unlock(&shared->lock);
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			add_wait_queue(&chip->wq, &wait);
+			spin_unlock(chip->mutex);
+			schedule();
+			remove_wait_queue(&chip->wq, &wait);
+			spin_lock(chip->mutex);
+			goto retry;
+		}
+
 		/* We now own it */
 		shared->writing = chip;
 		if (mode == FL_ERASING)