Subject: [PATCH v2] MTD/GPMI bugfix : reset the BCH module when it is not MX23

From: [email-masked] (Huang Shijie)
Date: Sat, 31 Dec 2011 10:23:50 +0800

Hi,
> On Fri, Dec 30, 2011 at 04:27:26PM +0800, Huang Shijie wrote:
>> In MX28, if we do not reset the BCH module. The BCH module may
>> becomes unstable when the board reboots for several thousands times.
> Do you have more details when and why this happens? What happens on MX23 then?
In one customer's 3G router which uses the MX28:
[0] NAND boot mode, mount the UBIFS in the NAND partition.
[1] We used the gpmi_reset_block(r->bch_regs, true) to init the BCH module.
[2] The board will automatically reboot again after it booted by NAND
boot mode.
[3] After reboot more then thousands times(cost nearly one day), the BCH
mode became UNSTABLE,
the data read out was not right, so the system could not mount the UBIFS.

After we use gpmi_reset_block(r->bch_regs, false) to init the BCH
module, the bug never happens.

The gpmi_reset_block() was coded to avoid the NAND boot bug in MX23. So
MX23 does not have the bug.
>> Signed-off-by: Huang Shijie <[email-masked]>
> Is this Bug 2847 from the errata? Should be mentioned in the commit message and
Yes, this is the bug 2847 from the mx23's errata.

I will add some comments to it.

Best Regards
Huang Shijie
> comments of the patch if so.
>
> Regards,
>
>    Wolfram
>