Re: [PATCH 1/3] cfi_cmdset_0001: Do not allow read/write to suspend erase block.

On Thu, Mar 1, 2018 at 2:39 PM, Joakim Tjernlund joakim.tjernlund@infinera.com wrote:

From: Joakim Tjernlund joakim.tjernlund@transmode.se

Currently it is possible to read and/or write to suspend EB's. Writing /dev/mtdX or /dev/mtdblockX from several processes may break the flash state machine.

Signed-off-by: Joakim Tjernlund joakim.tjernlund@infinera.com Cc: stable@vger.kernel.org

---

drivers/mtd/chips/cfi_cmdset_0001.c | 16 +++++++++++----- include/linux/mtd/flashchip.h | 1 + 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c index 60d5d19e347f..b59872304ae7 100644 --- a/drivers/mtd/chips/cfi_cmdset_0001.c +++ b/drivers/mtd/chips/cfi_cmdset_0001.c @@ -849,21 +849,25 @@ static int chip_ready (struct map_info *map, struct flchip *chip, unsigned long (mode == FL_WRITING && (cfip->SuspendCmdSupport & 1)))) goto sleep;

•           /* Do not allow suspend iff read/write to EB address */
  

•           if ((adr & chip->in_progress_block_mask) ==
  

•               chip->in_progress_block_addr)
  

•                   goto sleep;
  
            /* Erase suspend */
  

•           map_write(map, CMD(0xB0), adr);
  

•           map_write(map, CMD(0xB0), chip->in_progress_block_addr);
  
            /* If the flash has finished erasing, then 'erase suspend'
             * appears to make some (28F320) flash devices switch to
             * 'read' mode.  Make sure that we switch to 'read status'
             * mode so we get the right data. --rmk
             */
  

•           map_write(map, CMD(0x70), adr);
  

•           map_write(map, CMD(0x70), chip->in_progress_block_addr);
  

Why do you change to chip->in_progress_block_addr here?

            chip->oldstate = FL_ERASING;
            chip->state = FL_ERASE_SUSPENDING;
            chip->erase_suspended = 1;
            for (;;) {

•                   status = map_read(map, adr);
  

•                   status = map_read(map, chip->in_progress_block_addr);
                    if (map_word_andequal(map, status, status_OK, status_OK))
                            break;
  
  

@@ -1059,8 +1063,8 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad sending the 0x70 (Read Status) command to an erasing chip and expecting it to be ignored, that's what we do. */

•           map_write(map, CMD(0xd0), adr);
  

•           map_write(map, CMD(0x70), adr);
  

•           map_write(map, CMD(0xd0), chip->in_progress_block_addr);
  

•           map_write(map, CMD(0x70), chip->in_progress_block_addr);
            chip->oldstate = FL_READY;
            chip->state = FL_ERASING;
            break;
  

@@ -1951,6 +1955,8 @@ static int __xipram do_erase_oneblock(struct map_info *map, struct flchip *chip, map_write(map, CMD(0xD0), adr); chip->state = FL_ERASING; chip->erase_suspended = 0;

•   chip->in_progress_block_addr = adr;
  

•   chip->in_progress_block_mask = ~(len - 1);
  
    ret = INVAL_CACHE_AND_WAIT(map, chip, adr,
                               adr, len,
  

diff --git a/include/linux/mtd/flashchip.h b/include/linux/mtd/flashchip.h index b63fa457febd..3529683f691e 100644 --- a/include/linux/mtd/flashchip.h +++ b/include/linux/mtd/flashchip.h @@ -85,6 +85,7 @@ struct flchip { unsigned int write_suspended:1; unsigned int erase_suspended:1; unsigned long in_progress_block_addr;

•   unsigned long in_progress_block_mask;
  
    struct mutex mutex;
    wait_queue_head_t wq; /* Wait on here when we're waiting for the chip
  

-- 2.13.6

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