Hello Patrick,
On Mon, Jun 05, 2023 at 09:52:08AM +0200, Patrick Delaunay wrote:
> In the MTD DFU backend, it is needed to mark the NAND block bad when the
> erase failed with the -EIO error, as it is done in UBI and JFFS2 code.
>
> This operation is not done in the MTD framework, but the bad block
> tag (in BBM or in BBT) is required to avoid to write data on this block
> in the next DFU_OP_WRITE loop in mtd_block_op(): the code skip the bad
> blocks, tested by mtd_block_isbad().
>
> Without this patch, when the NAND block become bad on DFU write operation
> - low probability on new NAND - the DFU write operation will always failed
> because the failing block is never marked bad.
>
> This patch also adds a test to avoid to request an erase operation on a
> block already marked bad; this test is not performed in MTD framework
> in mtd_erase().
>
> Reviewed-by: Michael Trimarchi <mich...@amarulasolutions.com>
> Signed-off-by: Patrick Delaunay <patrick.delau...@foss.st.com>
Applied to nand-next,
thanks and regards,
Dario
> ---
>
> Changes in v3:
> - Split serie with trace fix and support of bad block in MTD erase
> - Fix trace for "bbt reserved" when mtd_block_isbad return 2
>
> Changes in v2:
> - fix mtd_block_isbad offset parameter for erase check
> - Add trace when bad block are skipped in erase loop
> - Add remaining byte in trace "Limit reached"
>
> drivers/dfu/dfu_mtd.c | 30 ++++++++++++++++++++++--------
> 1 file changed, 22 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/dfu/dfu_mtd.c b/drivers/dfu/dfu_mtd.c
> index b764f091786d..271d485d1c9a 100644
> --- a/drivers/dfu/dfu_mtd.c
> +++ b/drivers/dfu/dfu_mtd.c
> @@ -91,22 +91,36 @@ static int mtd_block_op(enum dfu_op op, struct dfu_entity
> *dfu,
> return -EIO;
> }
>
> + /* Skip the block if it is bad, don't erase it again */
> + ret = mtd_block_isbad(mtd, erase_op.addr);
> + if (ret) {
> + printf("Skipping %s at 0x%08llx\n",
> + ret == 1 ? "bad block" : "bbt reserved",
> + erase_op.addr);
> + erase_op.addr += mtd->erasesize;
> + continue;
> + }
> +
> ret = mtd_erase(mtd, &erase_op);
>
> if (ret) {
> - /* Abort if its not a bad block error */
> - if (ret != -EIO) {
> - printf("Failure while erasing at offset
> 0x%llx\n",
> - erase_op.fail_addr);
> - return 0;
> + /* If this is not -EIO, we have no idea what to
> do. */
> + if (ret == -EIO) {
> + printf("Marking bad block at 0x%08llx
> (%d)\n",
> + erase_op.fail_addr, ret);
> + ret = mtd_block_markbad(mtd,
> erase_op.addr);
> + }
> + /* Abort if it is not -EIO or can't mark bad */
> + if (ret) {
> + printf("Failure while erasing at offset
> 0x%llx (%d)\n",
> + erase_op.fail_addr, ret);
> + return ret;
> }
> - printf("Skipping bad block at 0x%08llx\n",
> - erase_op.addr);
> } else {
> remaining -= mtd->erasesize;
> }
>
> - /* Continue erase behind bad block */
> + /* Continue erase behind the current block */
> erase_op.addr += mtd->erasesize;
> }
> }
