[U-Boot] UBI: regression since "mtd: ubi: Fix worker handling"

[Patrice CHOTARD <patrice.chotard@st.com>]

Hi Richard, Heiko

Since 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.

As temporary workaround i did the following update on my side which fix 
this issue, but i don't consider it neither as a clean patch nor certain 
that it is enough :


@@ -1560,15 +1560,17 @@ int ubi_wl_init(struct ubi_device *ubi, struct 
ubi_attach_info *ai)
  			goto out_free;

  		e->pnum = aeb->pnum;
  		e->ec = aeb->ec;
  		ubi->lookuptbl[e->pnum] = e;
+		ubi->thread_enabled = 1;
  		if (schedule_erase(ubi, e, aeb->vol_id, aeb->lnum, 0)) {
+			ubi->thread_enabled = 0;
  			wl_entry_destroy(ubi, e);
  			goto out_free;
  		}
+		ubi->thread_enabled = 0;
  		found_pebs++;
  	}

  	list_for_each_entry(aeb, &ai->free, u.list) {


Regards

Patrice