[U-Boot] Porting UBI fixes (specially fastmap's) to U-Boot

[Heiko Schocher]

Hello Ezequiel,

Am 17.10.2015 um 20:07 schrieb Ezequiel Garcia:
> Hi Heiko,
>
> On 9 October 2015 at 09:30, Heiko Schocher <hs at denx.de> wrote:
> [..]
>>
>>
>> I just updated the "ubi_sync_with_linux" branch on u-boot-ubi.
>>
>> It seems UBI/UBIFS now work with the NAND on the aristainetos2
>> board, but my stomach says, there are some subtile issues ...
>>
>> Still needs more testing, also not tested yet UBI on the SPI NOR on
>> this board.
>>
>> If I "nand erase" the mtd device, and try "ubi part ..." it fails
>>
>> :-(
>>
>> But If I flash_eraseall under linux the device, and then make
>> "ubi part..." in U-Boot, commmand succeeds ...
>>
>
> Tested it on my custom AM335x board. Haven't used mainline U-Boot
> but cherry-picked the following commits:
>
>    linux, compat: add missing definitions for ubi
>    ubi/ubifs: some bugfixes
>    ubi,ubifs: sync with linux v4.2
>    ubi: reset mtd_devs when ubi part fail
>
> Commits apply cleanly except for "linux, compat: add missing
> definitions for ubi"
> which was trivial to backport anyway.
>
> U-Boot built fine, but there was a warning:
>
> drivers/mtd/ubi/fastmap.c: In function 'ubi_attach_fastmap':
> drivers/mtd/ubi/fastmap.c:816:2: warning: pointer targets in passing
> argument 3 of 'scan_pool' differ in signedness [-Wpointer-sign]
>    ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
>
> Just sent this patch which should fix it:
> http://patchwork.ozlabs.org/patch/531842/

Thanks for fixing. With it, I see no compiler warning anymore.
Applied to u-boot-ubi.git ubi_sync_with_linux

Tried this branch on the aristainetos2 board with ubi/ubifs on nand and
spi nor flash, worked fine, see log:

http://xeidos.ddns.net/buildbot/builders/ari_ubi/builds/7
http://xeidos.ddns.net/buildbot/builders/ari_ubi/builds/7/steps/shell/logs/tbotlog

> The board seems to work fine, and I can even to "nand erase" and "ubi
> part" without
> any problem.

Did you tried "ubi part" more than once in a row?

> However, I'm still seeing the same warning I had before, when my partition
> is attached:
>
> ubi0: default fastmap pool size: 200
> ubi0: default fastmap WL pool size: 100
> ubi0: attaching mtd1
> WARNING in drivers/mtd/ubi/fastmap.c line 846
> ubi0: scanning is finished
> ubi0: attached mtd1 (name "mtd=7", size 509 MiB)
> ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 129024 bytes
> ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 512
> ubi0: VID header offset: 512 (aligned 512), data offset: 2048
> ubi0: good PEBs: 4072, bad PEBs: 4, corrupted PEBs: 0
> ubi0: user volume: 4, internal volumes: 1, max. volumes count: 128
> ubi0: max/mean erase counter: 5/3, WL threshold: 4096, image sequence
> number: 2068197800
> ubi0: available PEBs: 3504, total reserved PEBs: 568, PEBs reserved
> for bad PEB handling: 76
>
> @Richard, any ideas? Do you know which of the fixes should fix that?

Does this warning raise also in linux? I do not see it on the aristainetos2
board.

U-Boot code:

        /*
          * If fastmap is leaking PEBs (must not happen), raise a
          * fat warning and fall back to scanning mode.
          * We do this here because in ubi_wl_init() it's too late
          * and we cannot fall back to scanning.
          */
#ifndef __UBOOT__
         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
                     ai->bad_peb_count - fm->used_blocks))
                 goto fail_bad;
#else
         if (count_fastmap_pebs(ai) != ubi->peb_count -
                     ai->bad_peb_count - fm->used_blocks) {
                 WARN_ON(1);
                 goto fail_bad;
         }
#endif

Hmm.. could not remember, why I did this U-Boot specific ...
But that;s a good example, why I like the "#ifndef __UBOOT__"
in Code ... I immediately see, if its linux or u-boot specific
code ... maybe its worth to try the original linux code?

bye,
Heiko
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