[U-Boot] [PATCH] sf: ensure flash device is in 3-byte address mode

[Jagan Teki]

On Mon, May 14, 2018 at 12:34 PM, Simon Goldschmidt
<sgoldschmidt at de.pepperl-fuchs.com> wrote:
> + Marek for the socfpga platform, see below
>
> On 07.12.2017 06:49, Jagan Teki wrote:
>>
>> On Tue, Dec 5, 2017 at 11:50 AM, Goldschmidt Simon
>> <sgoldschmidt at de.pepperl-fuchs.com> wrote:
>>>
>>> + Lukasz (as a reviewer of my patch[1])
>>>
>>> On Mon, Dec 4, 2017 at 8:20, Jagan Teki wrote:
>>>>
>>>> This is the patch[1] for 4-byte addressing, but I would wonder how can
>>>> proceed
>>>> operations with 4-byte if we disable during probe.
>>>>
>>>> [1] http://git.denx.de/?p=u-boot-
>>>> spi.git;a=commitdiff;h=fd0c22a90772379c4c11ba09347d36cc8ee17dca
>>>
>>>
>>> OK, so your patch does something different than what I did.
>>>
>>> I was trying to keep the change to U-Boot as small as possible, only
>>> fixing this issue I was seeing:
>>>
>>> After a soft-reboot where the SPI chip was not reset, it is left in
>>> 4-byte addressing mode (linux uses this mode, obviously). Remember
>>> that 4-byte mode is not a permanent setting, so we can enter and
>>> leave it any time we like by issuing a command.
>>>
>>> U-Boot uses the Bank Address Register (BAR) for spi flash chips with
>>> more than 16 MByte, so it impclitly assumes that the chip is in
>>> 3-byte address mode. As I see it, your patch is worth a discussion
>>> named "should we use 4-byte addressing mode on spi flash chips?".
>>> I do think this is a better alternative than writing BAR! But this
>>> change probably needs discussion and testing.
>>
>>
>> OK, will review your patch.
>
>
> Any update here? The last input on this is about five months old! This is
> the last patch I need to run my socfpga board from qspi.
>
> I added Marek to the discussion as at least the SoCrates board does not have
> a reset connected to the qspi chip and needs this as well. Note that the
> system boot rom does not have a problem with the chip being in 4-byte mode
> but SPL fails to load U-Boot from qspi.

Does Linux do this stuff? say my flash in 4-byte and flashed SPL and rebooted.