[Uclinux-dist-devel] [PATCH 4/7] mtd: Blackfin NFC: wait for the ECC reset to finish

[Mike Frysinger]

On Sun, Aug 15, 2010 at 22:54, Barry Song wrote:
> On Thu, Aug 5, 2010 at 11:16 PM, David Woodhouse wrote:
>> On Thu, 2010-08-05 at 11:07 -0400, Mike Frysinger wrote:
>>>
>>> +       while (bfin_read_NFC_RST() & ECC_RST)
>>> +               cpu_relax();
>>
>> All applied, but I'd be happier if this one had some kind of timeout and
>> didn't have the potential to loop forever if the hardware misbehaves.
>
> If this loop forever, it means a chip bug and really has no any way to
> continue to run the system. So the point is "bfin_read_NFC_RST() &
> ECC_RST" will must be real for the right chip, if the chip has bug,
> there should be workaround but not a timeout.

i think the presumption on the linux/driver side is that hardware has
the tendency to suck, so rather than hang the whole system because the
NFC flakes out, it should recover gracefully.  so spitting out NAND
I/O errors all over the console is preferable to a system that goes
nowhere.

personally, i think it depends on the driver/situation, and in the
embedded world, i tend to agree with you Barry in that a dead subpiece
is the same as the whole system being dead.  but my opinion doesnt
matter much if the subsystem maintainers reject the patches ;).
-mike