[U-Boot] [PATCH] mtd, ubi: set free_count to zero before walking through erase list

[Richard Weinberger]

Am 02.02.2016 um 11:54 schrieb Heiko Schocher:
> Set free_count to zero before walking through ai->erase list
> in wl_init().
> 
> As U-Boot has no workqueue/threads, it immediately calls
> erase_worker(), which increase for each erased block
> free_count. Without this patch, free_count gets after
> this initialized to zero in wl_init(), so the free_count
> variable always has the maybe wrong value 0.
> 
> Detected this behaviour on the dxr2 board, where the
> UBI fastmap gets not written when attaching/dettaching
> on an empty NAND. It drops instead the error message:
> 
> could not find any anchor PEB
> 
> With this patch, fastmap gets written on dettach.
> 
> Signed-off-by: Heiko Schocher <hs at denx.de>
> ---
> added Richard to this EMail, as maybe this could be a problem
> in linux too ... ?

ubi_wl_init() is called by ubi_attach().
So, as soon your UBI image is attached the WL subsystem
is fully initialized and ready to use.
If you try to use it before you're in undefined state.
u-boot must not run the erase_worker() before the attach
phase is done.

Do you have more details what exactly happened?
This needs a deeper investigation.

Thanks,
//richard