Re: [PATCH] NAND: Fix NAND ECC errors on AMD Au1550

[Sergei Shtylylov <sshtylyov@ru.mvista.com>]

Hello.

Leif Lindholm wrote:

>>    Note, that with NAND_CMD_READID page_addr of -1 is always passed (so we 
>>only write out the 1-byte column address) on the address phase, and we just 
>>won't get there for READID command....

>>    Therefore, neither -CE wil be overridden nor local_irq_save() be executed 
>>for READID case...

> Well, I guess I cheated a bit.

    Especially with separation of setting ce_override to 1 and a real -CE
override -- that's a potentially dangerous trick. :-)

> In the more well-tested version of the driver (using your older patch),

    Do you mean the patch originally posted? I wasn't participating in it then
(woulnd't even have posted such stuff :-).

> I actually do the force-assert for (column != -1) as well.

    I guess, you'd better set ce_override to 1 at the exact place where you
start to override -CE.

>>    Has your READID problem arisen with or without my patch?

> Your patch fixed the problem of a collision with the NOR flash.
> But only after I added the READID force-assert. Before that it caused
> the NAND chip to stop being detected.

    Kind of strange. I have the datasheet of that Samsung part before me, and
it doesn't even have R/-B line on the Read ID timing diagrams...

WBR, Sergei