On 06.08.2018 17:33, Simon Goldschmidt wrote:
Stefan Roese <s...@denx.de <mailto:s...@denx.de>> schrieb am Mo., 6. Aug.
2018, 17:29:
On 06.08.2018 17:27, Simon Goldschmidt wrote:
>
>
> Stefan Roese <s...@denx.de <mailto:s...@denx.de> <mailto:s...@denx.de
<mailto:s...@denx.de>>> schrieb am Mo., 6. Aug.
> 2018, 17:23:
>
> Hi Simon,
>
> On 06.08.2018 17:15, Simon Goldschmidt wrote:
> >
> >
> > Stefan Roese <s...@denx.de <mailto:s...@denx.de>
<mailto:s...@denx.de <mailto:s...@denx.de>> <mailto:s...@denx.de
<mailto:s...@denx.de>
> <mailto:s...@denx.de <mailto:s...@denx.de>>>> schrieb am Mo., 6. Aug.
> > 2018, 16:34:
> >
> > Some SPI NOR chips only support 4-byte mode
addressing. Here
> the default
> > 3-byte mode does not work and leads to incorrect accesses.
> Setting this
> > option enables the use of such SPI NOR chips, that only
> support this
> > 4-byte mode.
> >
> >
> > I think it would make more sense to enable 4-byte mode or
4-byte
> opcodes
> > on all chips with more than 16 mbyte rather than having to
select at
> > compile time.
>
> We need to be careful here. As setting the chip into 4-byte mode
> unconditionally (for bigger devices) will very likely cause boot
> problems with internal bootROMs expecting 3-byte mode.
>
>
> I have a similar problem on socfpga where Linux 4.9 sets the chip
into
> 4-byte mode and SPL cannot use it on warm reboot. However, the
bootROM
> does not run on warm reboot on this platform.
So in your "warm reboot" case, my option b) below would help, right?
Yes, I guess it would.
An even better idea would be to use stateless 4-byte opcodes. That's
what Linux does in more recent versions. But that would be a larger
patch, I guess. And with Jagan's bigger rework in his queue, I can't
tell if this is a good time to do so.
Yes, this is definitely out of scope for me, reworking this 4-byte
support to this stateless version. Sorry. But if we agree that the
option b) is helpful and harmless (which I think it is), then I
can rework this patch and re-send a version which should also work
for you - as described below.
b)
Another idea would be to check the 3-byte / 4-byte mode of the SPI
NOR device upon SPI NOR driver loading and use the selected mode
accordingly. This could be done without compile time options but
it would not help in general for users with bigger SPI NOR devices
that support both modes.
Thanks,
Stefan
Thanks,
Stefan
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