[U-Boot] [PATCH v2 3/4] sf: Read back and check once macronix quad bit set

[Mugunthan V N <mugunthanvnm@ti.com>]

On Wednesday 23 December 2015 01:51 PM, Jagan Teki wrote:
> On 23 December 2015 at 13:22, Mugunthan V N <mugunthanvnm@ti.com> wrote:
>> On Wednesday 16 December 2015 02:31 PM, Jagan Teki wrote:
>>> One macronix quad bit set using SR, it's good to
>>> read back and check the written bit and also if
>>> it's already been set check for the bit and return.
>>>
>>> Cc: Vignesh R <vigneshr@ti.com>
>>> Cc: Mugunthan V N <mugunthanvnm@ti.com>
>>> Cc: Simon Glass <sjg@chromium.org>
>>> Cc: Bin Meng <bmeng.cn@gmail.com>
>>> Signed-off-by: Jagan Teki <jteki@openedev.com>
>>> ---
>>> Changes for v2:
>>>       - none
>>>
>>>  drivers/mtd/spi/spi_flash.c | 18 ++++++++++++------
>>>  1 file changed, 12 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
>>> index ba6651e..c922322 100644
>>> --- a/drivers/mtd/spi/spi_flash.c
>>> +++ b/drivers/mtd/spi/spi_flash.c
>>> @@ -840,12 +840,18 @@ static int macronix_quad_enable(struct spi_flash *flash)
>>>       if (ret < 0)
>>>               return ret;
>>>
>>> -     if (qeb_status & STATUS_QEB_MXIC) {
>>> -             debug("SF: mxic: QEB is already set\n");
>>> -     } else {
>>> -             ret = write_sr(flash, STATUS_QEB_MXIC);
>>> -             if (ret < 0)
>>> -                     return ret;
>>> +     if (qeb_status & STATUS_QEB_MXIC)
>>> +             return 0;
>>> +
>>> +     ret = write_sr(flash, STATUS_QEB_MXIC);
>>> +     if (ret < 0)
>>> +             return ret;
>>> +
>>> +     /* read SR and check it */
>>> +     ret = read_sr(flash, &qeb_status);
>>> +     if (!(ret > 0 && (qeb_status & STATUS_QEB_MXIC))) {
>>
>> This error check is wrong, it can be either one of the below
>>
>> if (!(ret >= 0 && (qeb_status & STATUS_QEB_MXIC))) {
> 
> So =0 is a success case, this is what you pointing to correct? did you
> test this?

Yeah, I have tested this on am437x-sk evm.

The same fix has to be done for spansion flash as well!

Regards
Mugunthan V N