reboot problem with MPC8248 based board

reboot problem with MPC8248 based board

[Jianlin Zeng]

Hi,

I have a MPC8248 based board running with linux kernel
2.6.11. I mounted jffs2 FS on a NOR flash devices. The
jffs2 FS works fine. But whenever I modify any files
in jffs2 FS and soft reboot the board, the reboot
hangs. If I don't modify any files in jffs2 FS and
just do flashcp to mtd char device, the soft reboot
works fine.

I tried doing "reboot" through "m8260_gorom" or a
mechanism similar to what is used in u-boot. The
result is the same. I don't understand why jffs2 write
causes reboot to hang but MTD char device write does
not. Does anybody have similar experience? Can anybody
give me some help?

Thanks,
Jianlin


 
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Re: reboot problem with MPC8248 based board

[Jeff Angielski]

On Fri, 2006-12-08 at 17:25 -0800, Jianlin Zeng wrote:
> Hi,
> 
> I have a MPC8248 based board running with linux kernel
> 2.6.11. I mounted jffs2 FS on a NOR flash devices. The
> jffs2 FS works fine. But whenever I modify any files
> in jffs2 FS and soft reboot the board, the reboot
> hangs. If I don't modify any files in jffs2 FS and
> just do flashcp to mtd char device, the soft reboot
> works fine.
> 
> I tried doing "reboot" through "m8260_gorom" or a
> mechanism similar to what is used in u-boot. The
> result is the same. I don't understand why jffs2 write
> causes reboot to hang but MTD char device write does
> not. Does anybody have similar experience? Can anybody
> give me some help?
> 
> Thanks,
> Jianlin

I have seen strange reboot behavior like this when the flash chips were
left in write mode.  After reboot, you are unable to read the flash and
the system just hangs.  

In 2.4 days, we solved this with a reboot_notifier that just went
through the sectors and reset them back to read mode.

Not sure if that helps but at least it gives you something to look into.



-- 
Jeff Angielski
The PTR Group

Re: reboot problem with MPC8248 based board

[Jianlin Zeng]

Hi Jeff,

Thanks a lot for your information! That's indeed the
reason for the hang. Now I read through all flash
sectors before reboot and it works fine.

Regards,
Jianlin



--- Jeff Angielski <jeff@theptrgroup.com> wrote:

> On Fri, 2006-12-08 at 17:25 -0800, Jianlin Zeng
> wrote:
> > Hi,
> > 
> > I have a MPC8248 based board running with linux
> kernel
> > 2.6.11. I mounted jffs2 FS on a NOR flash devices.
> The
> > jffs2 FS works fine. But whenever I modify any
> files
> > in jffs2 FS and soft reboot the board, the reboot
> > hangs. If I don't modify any files in jffs2 FS and
> > just do flashcp to mtd char device, the soft
> reboot
> > works fine.
> > 
> > I tried doing "reboot" through "m8260_gorom" or a
> > mechanism similar to what is used in u-boot. The
> > result is the same. I don't understand why jffs2
> write
> > causes reboot to hang but MTD char device write
> does
> > not. Does anybody have similar experience? Can
> anybody
> > give me some help?
> > 
> > Thanks,
> > Jianlin
> 
> I have seen strange reboot behavior like this when
> the flash chips were
> left in write mode.  After reboot, you are unable to
> read the flash and
> the system just hangs.  
> 
> In 2.4 days, we solved this with a reboot_notifier
> that just went
> through the sectors and reset them back to read
> mode.
> 
> Not sure if that helps but at least it gives you
> something to look into.
> 
> 
> 
> -- 
> Jeff Angielski
> The PTR Group
> 
> 



 
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