[U-Boot] UBI: volume auto-resize

[U-Boot] UBI: volume auto-resize

[Matevz Langus]

Hi,

I found an interesting situation where I can not decide whether it is a bug or functionality that should not be included at all.

If I generate UBI image consisting of 3 Volumes to NAND flash on my board, U-boot  does not attach UBI to MTD. This happens only if UBI contains a volume that has auto-resize flag set.
U-boot tries to resize it but fails.

Just started fixing it, but I have a question. Is it desirable that U-boot changes something in the FS? Would it not be better if U-boot would just read things out (that is all I want, to get uImage and dtb file) and leave the rest to Linux.
(Linux handles the procedure without any issues).

Any opinion welcome.

Creating 1 MTD partitions on "nand0":
0x000000200000-0x000008000000 : "mtd=2"
Bad block table found at page 65472, version 0x01
Bad block table found at page 65408, version 0x01
nand_read_bbt: Bad block at 0x0000011a0000
UBI: attaching mtd1 to ubi0
UBI: physical eraseblock size:   131072 bytes (128 KiB)
UBI: logical eraseblock size:    129024 bytes
UBI: smallest flash I/O unit:    2048
UBI: sub-page size:              512
UBI: VID header offset:          512 (aligned 512)
UBI: data offset:                2048
UBI error: ubi_io_write: error -5 while writing 512 bytes to PEB 1003:512, written 0 bytes
UBI warning: ubi_eba_write_leb: failed to write VID header to LEB 2147479551:0, PEB 1003
UBI: try another PEB
UBI error: ubi_io_write: error -5 while writing 512 bytes to PEB 1003:512, written 0 bytes
UBI warning: ubi_eba_write_leb: failed to write VID header to LEB 2147479551:0, PEB 1003
UBI: try another PEB
UBI error: ubi_io_write: error -5 while writing 512 bytes to PEB 1003:512, written 0 bytes
UBI warning: ubi_eba_write_leb: failed to write VID header to LEB 2147479551:0, PEB 1003
UBI: try another PEB
UBI error: ubi_io_write: error -5 while writing 512 bytes to PEB 1003:512, written 0 bytes
UBI warning: ubi_eba_write_leb: failed to write VID header to LEB 2147479551:0, PEB 1003
UBI warning: ubi_ro_mode: switch to read-only mode
UBI error: autoresize: cannot auto-resize volume 2
UBI error: ubi_init: cannot attach mtd1
UBI error: ubi_init: UBI error: cannot initialize UBI, error -30
UBI init error 30


Best regards,
  Matevz Langus

[U-Boot] UBI: volume auto-resize

[Marek Vasut]

Dear Matevz Langus,

> Hi,
> 
> I found an interesting situation where I can not decide whether it is a bug
> or functionality that should not be included at all.
> 
> If I generate UBI image consisting of 3 Volumes to NAND flash on my board,
> U-boot  does not attach UBI to MTD. This happens only if UBI contains a
> volume that has auto-resize flag set. U-boot tries to resize it but fails.
> 
> Just started fixing it, but I have a question. Is it desirable that U-boot
> changes something in the FS? Would it not be better if U-boot would just
> read things out (that is all I want, to get uImage and dtb file) and leave
> the rest to Linux. (Linux handles the procedure without any issues).
> 
> Any opinion welcome.
> 
> Creating 1 MTD partitions on "nand0":
> 0x000000200000-0x000008000000 : "mtd=2"
> Bad block table found at page 65472, version 0x01
> Bad block table found at page 65408, version 0x01
> nand_read_bbt: Bad block at 0x0000011a0000
> UBI: attaching mtd1 to ubi0
> UBI: physical eraseblock size:   131072 bytes (128 KiB)
> UBI: logical eraseblock size:    129024 bytes
> UBI: smallest flash I/O unit:    2048
> UBI: sub-page size:              512

Is the subpage size here correct? I know at least about one driver that might 
misreport it under certain conditions.

Best regards,
Marek Vasut

[U-Boot] UBI: volume auto-resize

[Matevz Langus]

Hi,

Thanks, initial problem about the subpage size was solved fast. The question still remains, is it wise to let u-boot resize volumes if it only boots from one of the volumes.

Matevz Langus

On 13. maj 2012, at 19:09, Marek Vasut <marek.vasut@gmail.com> wrote:

> Dear Matevz Langus,
> 
>> Hi,
>> 
>> I found an interesting situation where I can not decide whether it is a bug
>> or functionality that should not be included at all.
>> 
>> If I generate UBI image consisting of 3 Volumes to NAND flash on my board,
>> U-boot  does not attach UBI to MTD. This happens only if UBI contains a
>> volume that has auto-resize flag set. U-boot tries to resize it but fails.
>> 
>> Just started fixing it, but I have a question. Is it desirable that U-boot
>> changes something in the FS? Would it not be better if U-boot would just
>> read things out (that is all I want, to get uImage and dtb file) and leave
>> the rest to Linux. (Linux handles the procedure without any issues).
>> 
>> Any opinion welcome.
>> 
>> Creating 1 MTD partitions on "nand0":
>> 0x000000200000-0x000008000000 : "mtd=2"
>> Bad block table found at page 65472, version 0x01
>> Bad block table found at page 65408, version 0x01
>> nand_read_bbt: Bad block at 0x0000011a0000
>> UBI: attaching mtd1 to ubi0
>> UBI: physical eraseblock size:   131072 bytes (128 KiB)
>> UBI: logical eraseblock size:    129024 bytes
>> UBI: smallest flash I/O unit:    2048
>> UBI: sub-page size:              512
> 
> Is the subpage size here correct? I know at least about one driver that might 
> misreport it under certain conditions.
> 
> Best regards,
> Marek Vasut

[U-Boot] UBI: volume auto-resize

[Marek Vasut]

Dear Matevz Langus,

> Hi,
> 
> Thanks, initial problem about the subpage size was solved fast.

How, so you can only use 2048b big subpage?

> The
> question still remains, is it wise to let u-boot resize volumes if it only
> boots from one of the volumes.

Sure, why not?

btw please avoid top-posting when replying to emails.

> 
> Matevz Langus
> 
> On 13. maj 2012, at 19:09, Marek Vasut <marek.vasut@gmail.com> wrote:
> > Dear Matevz Langus,
> > 
> >> Hi,
> >> 
> >> I found an interesting situation where I can not decide whether it is a
> >> bug or functionality that should not be included at all.
> >> 
> >> If I generate UBI image consisting of 3 Volumes to NAND flash on my
> >> board, U-boot  does not attach UBI to MTD. This happens only if UBI
> >> contains a volume that has auto-resize flag set. U-boot tries to resize
> >> it but fails.
> >> 
> >> Just started fixing it, but I have a question. Is it desirable that
> >> U-boot changes something in the FS? Would it not be better if U-boot
> >> would just read things out (that is all I want, to get uImage and dtb
> >> file) and leave the rest to Linux. (Linux handles the procedure without
> >> any issues).
> >> 
> >> Any opinion welcome.
> >> 
> >> Creating 1 MTD partitions on "nand0":
> >> 0x000000200000-0x000008000000 : "mtd=2"
> >> Bad block table found at page 65472, version 0x01
> >> Bad block table found at page 65408, version 0x01
> >> nand_read_bbt: Bad block at 0x0000011a0000
> >> UBI: attaching mtd1 to ubi0
> >> UBI: physical eraseblock size:   131072 bytes (128 KiB)
> >> UBI: logical eraseblock size:    129024 bytes
> >> UBI: smallest flash I/O unit:    2048
> >> UBI: sub-page size:              512
> > 
> > Is the subpage size here correct? I know at least about one driver that
> > might misreport it under certain conditions.
> > 
> > Best regards,
> > Marek Vasut

Best regards,
Marek Vasut

[U-Boot] UBI: volume auto-resize

[Matevz Langus]

Hi,

sorry for top-posting.

It is Freescale eLB NAND controller. We need to investigate a bit more why it does not work with 512B sub-pages in u-boot. It does in Linux.

In my case, I do not want to update boot-loader in the future. If any bugs in UBI are found, we can cope with  this in Linux. As long as boot-loader only reads, it can not do any damage. Resizing is not read only operation.

regards,
  Matevz Langus

[U-Boot] UBI: volume auto-resize

[Marek Vasut]

Dear Matevz Langus,

> Hi,
> 
> sorry for top-posting.
> 
> It is Freescale eLB NAND controller. We need to investigate a bit more why
> it does not work with 512B sub-pages in u-boot. It does in Linux.

And are you sure it does use 512b subpages in linux? Because I think there's 
still a bug in linux that forces these controllers (at least the GPMI NAND) to 
use 2048b subpages.

> 
> In my case, I do not want to update boot-loader in the future. If any bugs
> in UBI are found, we can cope with  this in Linux. As long as boot-loader
> only reads, it can not do any damage. Resizing is not read only operation.

Oh ok.

> 
> regards,
>   Matevz Langus

Best regards,
Marek Vasut

[U-Boot] UBI: volume auto-resize

[Scott Wood]

On 05/15/2012 11:33 AM, Marek Vasut wrote:
> Dear Matevz Langus,
> 
>> Hi,
>>
>> sorry for top-posting.
>>
>> It is Freescale eLB NAND controller. We need to investigate a bit more why
>> it does not work with 512B sub-pages in u-boot. It does in Linux.
> 
> And are you sure it does use 512b subpages in linux? Because I think there's 
> still a bug in linux that forces these controllers (at least the GPMI NAND) to 
> use 2048b subpages.

eLBC hardware does not support doing ECC on subpage accesses (and thus
the driver does not support subpage accesses at all).  How does UBI use
subpage accesses?

-Scott

[U-Boot] UBI: volume auto-resize

[Matevz Langus]

Hi Scott,

yes, I have also seen that. That makes me think using 2k alignment for  
all UBI structure is the safest/only way to go with eLBC NAND.
But really confused I was, when I saw it working in Linux. Maybe Linux  
driver does not use HW ECC. Will report the findings when I finish  
other things.

regards,
   Matevz