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

[Marek Vasut]

On 06/04/2018 08:35 PM, Jagan Teki wrote:
> On Tue, Jun 5, 2018 at 12:02 AM, Marek Vasut <marex at denx.de> wrote:
>> On 06/04/2018 08:03 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.
>>>>
>>>> This is because the erase command will call write_bar()+clean_bar(),
>>>> which will leave flash->bank_curr = 1 while the hardware BAR registers
>>>> will be set to 0 through clean_bar(). The subsequent write will also
>>>> trigger write_bar()+clean_bar(), but write_bar checks if the target
>>>> bank == flash->bank_curr and if so, does NOT reconfigure the BAR in
>>>> the SPI NOR. Since flash->bank_curr is still 1 and out of sync with
>>>> the HW, the condition matches, BAR programming is skipped and write
>>>> ends up at address 0x0, thus corrupting flash content.
>>>>
>>>> Signed-off-by: Marek Vasut <marex at denx.de>
>>>> Cc: Jagan Teki <jagan at openedev.com>
>>>> Cc: Tom Rini <trini at konsulko.com>
>>>
>>> Reviewed-by: Jagan Teki <jagan at openedev.com>
>>>
>>> Applied to u-boot-spi/master
>>
>> So I presume you see it now ?
> 
> Yes, I understand the issue, thanks.

Excellent

-- 
Best regards,
Marek Vasut