diff options
| author | Joakim Tjernlund <Joakim.Tjernlund@transmode.se> | 2011-02-07 17:07:11 +0100 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2011-03-11 12:09:07 +0000 |
| commit | ecf3fde07c8dcb92a1bf3fbdfe70905d85cd00e1 (patch) | |
| tree | b45b4729fdd5e49f588629a3da968a4a90aa401f /drivers | |
| parent | ceabebb2bd2672f709e4454e16bc6042732e2dfe (diff) | |
mtd: fix race in cfi_cmdset_0001 driver
As inval_cache_and_wait_for_operation() drop and reclaim the lock
to invalidate the cache, some other thread may suspend the operation
before reaching the for(;;) loop. Therefore the loop must start with
checking the chip->state before reading status from the chip.
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Acked-by: Michael Cashwell <mboards@prograde.net>
Acked-by: Stefan Bigler <stefan.bigler@keymile.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mtd/chips/cfi_cmdset_0001.c | 43 |
1 files changed, 22 insertions, 21 deletions
diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c index a8c3e1c9b02..4aaa88f8ab5 100644 --- a/drivers/mtd/chips/cfi_cmdset_0001.c +++ b/drivers/mtd/chips/cfi_cmdset_0001.c @@ -1230,10 +1230,32 @@ static int inval_cache_and_wait_for_operation( sleep_time = chip_op_time / 2; for (;;) { + if (chip->state != chip_state) { + /* Someone's suspended the operation: sleep */ + DECLARE_WAITQUEUE(wait, current); + set_current_state(TASK_UNINTERRUPTIBLE); + add_wait_queue(&chip->wq, &wait); + mutex_unlock(&chip->mutex); + schedule(); + remove_wait_queue(&chip->wq, &wait); + mutex_lock(&chip->mutex); + continue; + } + status = map_read(map, cmd_adr); if (map_word_andequal(map, status, status_OK, status_OK)) break; + if (chip->erase_suspended && chip_state == FL_ERASING) { + /* Erase suspend occured while sleep: reset timeout */ + timeo = reset_timeo; + chip->erase_suspended = 0; + } + if (chip->write_suspended && chip_state == FL_WRITING) { + /* Write suspend occured while sleep: reset timeout */ + timeo = reset_timeo; + chip->write_suspended = 0; + } if (!timeo) { map_write(map, CMD(0x70), cmd_adr); chip->state = FL_STATUS; @@ -1257,27 +1279,6 @@ static int inval_cache_and_wait_for_operation( timeo--; } mutex_lock(&chip->mutex); - - while (chip->state != chip_state) { - /* Someone's suspended the operation: sleep */ - DECLARE_WAITQUEUE(wait, current); - set_current_state(TASK_UNINTERRUPTIBLE); - add_wait_queue(&chip->wq, &wait); - mutex_unlock(&chip->mutex); - schedule(); - remove_wait_queue(&chip->wq, &wait); - mutex_lock(&chip->mutex); - } - if (chip->erase_suspended && chip_state == FL_ERASING) { - /* Erase suspend occured while sleep: reset timeout */ - timeo = reset_timeo; - chip->erase_suspended = 0; - } - if (chip->write_suspended && chip_state == FL_WRITING) { - /* Write suspend occured while sleep: reset timeout */ - timeo = reset_timeo; - chip->write_suspended = 0; - } } /* Done and happy. */ |