mtd: fix hang-up in cfi erase and read contention

cfi erase command hangs up when erase and read contention occurs.
If read runs at the same address as erase operation, read issues
Erase-Suspend via get_chip() and the erase goes into sleep in wait queue.
But in this case, read operation exits by time-out without waking it up.

I think the other variants (0001, 0020 and lpddr) have the same problem too.
Tested and verified the patch only on CFI-0002 flash, though.

Signed-off-by: Tadashi Abe <tabe@mvista.com>
Acked-by: Joakim Tjernlund <joakim.tjernlund@transmode.se>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

3 files changed, 5 insertions, 9 deletions

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index 09cb7c8d93b4..121be022d1ea 100644
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -812,12 +812,9 @@ static int chip_ready (struct map_info *map, struct flchip *chip, unsigned long
                                 break;
 
                         if (time_after(jiffies, timeo)) {
-                                /* Urgh. Resume and pretend we weren't here.  */
-                                map_write(map, CMD(0xd0), adr);
-                                /* Make sure we're in 'read status' mode if it had finished */
-                                map_write(map, CMD(0x70), adr);
-                                chip->state = FL_ERASING;
-                                chip->oldstate = FL_READY;
+                                /* Urgh. Resume and pretend we weren't here.
+                                 * Make sure we're in 'read status' mode if it had finished */
+                                put_chip(map, chip, adr);
                                 printk(KERN_ERR "%s: Chip not ready after erase "
                                        "suspended: status = 0x%lx\n", map->name, status.x[0]);
                                 return -EIO;
diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index b890f6c964d9..9a99a5bd3ea5 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -711,9 +711,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr
                                  * there was an error (so leave the erase
                                  * routine to recover from it) or we trying to
                                  * use the erase-in-progress sector. */
-                                map_write(map, cfi->sector_erase_cmd, chip->in_progress_block_addr);
-                                chip->state = FL_ERASING;
-                                chip->oldstate = FL_READY;
+                                put_chip(map, chip, adr);
                                 printk(KERN_ERR "MTD %s(): chip not ready after erase suspend\n", __func__);
                                 return -EIO;
                         }
diff --git a/drivers/mtd/chips/cfi_cmdset_0020.c b/drivers/mtd/chips/cfi_cmdset_0020.c
index ed56ad3884fb..179814a95f3a 100644
--- a/drivers/mtd/chips/cfi_cmdset_0020.c
+++ b/drivers/mtd/chips/cfi_cmdset_0020.c
@@ -296,6 +296,7 @@ static inline int do_read_onechip(struct map_info *map, struct flchip *chip, lof
                                 /* make sure we're in 'read status' mode */
                                 map_write(map, CMD(0x70), cmd_addr);
                                 chip->state = FL_ERASING;
+                                wake_up(&chip->wq);
                                 mutex_unlock(&chip->mutex);
                                 printk(KERN_ERR "Chip not ready after erase "
                                        "suspended: status = 0x%lx\n", status.x[0]);