[U-Boot] [PATCH] sf: Set current flash bank to 0 in clean_bar()

[Jagan Teki]

On Mon, Jun 4, 2018 at 7:05 PM, Marek Vasut <marex at denx.de> wrote:
> On 06/04/2018 03:27 PM, Jagan Teki wrote:
>> On Fri, May 25, 2018 at 1:28 AM, Marek Vasut <marex at denx.de> wrote:
>>> The clean_bar() function resets the SPI NOR BAR register to 0, but
>>> does not set the flash->curr_bar to 0 , therefore those two can get
>>> out of sync, which could ultimatelly result in corrupted flash content.
>>>
>>> The simplest test case is this:
>>>
>>>   => mw 0x10000000 0x1234abcd 0x4000
>>>   => sf probe
>>>   => sf erase 0x1000000 0x10000
>>>   => sf write 0x10000000 0x1000000 0x10000
>>>
>>>   => sf probe ; sf read 0x12000000 0 0x10000 ; md 0x12000000
>>>
>>> That is, erase a sector above the 16 MiB boundary and write it with
>>> random pre-configured data. What will actually happen without this
>>> patch is the sector will be erased, but the data will be written to
>>> BAR 0 offset 0x0 in the flash.

What I'm trying to say is both erase and write ops we have write_bar
to switch specific offset of flash based on the bank_sel and the same
bank_sel is updated in flash->bank_curr. If there is an immediate read
after we still computing bank_sel and do necessary ops. for each
operation completion the clean_bar will switch the flash to 0x0 offset
by writing bank_sel as 0

What is corrupting here? can you explain?