Since 'commit f82290afc847 ("mtd: ubi: Fix worker handling")', when booting from NAND, on a fresh NAND just after being flashed (and only in this case), we got the following log:

ubi0: default fastmap pool size: 200 ubi0: default fastmap WL pool size: 100 ubi0: attaching mtd2 ubi0: scanning is finished ubi0 error: ubi_update_fastmap: could not find any anchor PEB ubi0 error: ubi_update_fastmap: could not find any anchor PEB ubi0 error: ubi_wl_get_peb: Unable to get a free PEB from user WL pool ubi0 error: autoresize: cannot auto-resize volume 1 UBI error: cannot attach mtd2UBI error: cannot initialize UBI, error -28UBI init error 28

After analysis, in ubi_wl_init(), when performing schedule_erase(), thread_enabled flag is not yet set to 1, which forbids ubi_do_worker() to execute pending works.

This has to effect to not populate ubi->free with free physical eraseblocks.

Following Richard Weinberger's advice, this patch has been backported from kernel tree : 'commit 1cb8f9776c7d ("ubi: fastmap: Implement produce_free_peb()")'

Tested-by: Patrice Chotard patrice.chotard@st.com Signed-off-by: Richard Weinberger richard@nod.at Signed-off-by: Patrice Chotard patrice.chotard@st.com ---

drivers/mtd/ubi/fastmap-wl.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+)

diff --git a/drivers/mtd/ubi/fastmap-wl.c b/drivers/mtd/ubi/fastmap-wl.c index b7876a81cb0f..e36fb39943a5 100644 --- a/drivers/mtd/ubi/fastmap-wl.c +++ b/drivers/mtd/ubi/fastmap-wl.c @@ -171,6 +171,30 @@ void ubi_refill_pools(struct ubi_device *ubi) }

/** + * produce_free_peb - produce a free physical eraseblock. + * @ubi: UBI device description object + * + * This function tries to make a free PEB by means of synchronous execution of + * pending works. This may be needed if, for example the background thread is + * disabled. Returns zero in case of success and a negative error code in case + * of failure. + */ +static int produce_free_peb(struct ubi_device *ubi) +{ + int err; + + while (!ubi->free.rb_node && ubi->works_count) { + dbg_wl("do one work synchronously"); + err = do_work(ubi); + + if (err) + return err; + } + + return 0; +} + +/** * ubi_wl_get_peb - get a physical eraseblock. * @ubi: UBI device description object * @@ -212,6 +236,11 @@ again: } retried = 1; up_read(&ubi->fm_eba_sem); + ret = produce_free_peb(ubi); + if (ret < 0) { + down_read(&ubi->fm_eba_sem); + goto out; + } goto again; }