Re: [i.MX28 GPMI] problem overwriting all-0xff data in NAND

Wolfram Sang
2011-07-20T08:51:55Z

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> >>>>>I am debugging the DMA bug now. and I will send it out when i fix it.
> >>>>>
> >>>>What sort of DMA bug?
> >>>>
> >>>The DMA may time-out. :(
> >>>
> >>>The DMA time-out may occur in two situations:
> >>>[1] send a command DMA descriptor, see the nfc->send_command() function.
> >>>[2] read the non-ecc data from nand, see the nfc->read_data() function.
> >>>
> >>>I don't know why. Maybe caused by the timing, or something else.
> >I am confused. The send-command DMA timeout prevents any write for me.
> >You guys surely would have noticed if you have been bitten as well. Does
> >it depend on the NAND chip?
> I think It does not depend on the NAND chip.
> My test chip is Samsung K9G8G08U0M.
> Sometimes, I can run a long time while there is no DMA timeout occurring;
> Sometimes, the bug appears right away.

For me, the bug always happens right away. So, if you need logs or debug
output or can give me a pointer into some direction, I am glad to
assist.

--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |

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