[PATCH] mtd: spi-nor: wait until lock/unlock operations are ready

[Ezequiel Garcia]

Brian,

On 15 December 2015 at 15:12, Brian Norris <computersforpeace at gmail.com> wrote:
> On Sun, Nov 22, 2015 at 10:09:57PM -0300, Ezequiel Garcia wrote:
>> On Micron and Numonyx devices, the status register write command
>> (WRSR), raises a work-in-progress bit (WIP) on the status register.
>> The datasheets for these devices specify that while the status
>> register write is in progress, the status register WIP bit can still
>> be read to check the end of the operation.
>>
>> This commit adds a wait_till_ready call on lock/unlock operations,
>> only for these manufacturers. This is needed to prevent applications
>> from issuing erase or program operations before the unlock operation
>> is completed.
>>
>> Reported-by: Stas Sergeev <stsp at list.ru>
>> Signed-off-by: Ezequiel Garcia <ezequiel at vanguardiasur.com.ar>
>> ---
>>  drivers/mtd/spi-nor/spi-nor.c | 18 ++++++++++++++++--
>>  1 file changed, 16 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
>> index e9c26c0e2258..acc9b05e02be 100644
>> --- a/drivers/mtd/spi-nor/spi-nor.c
>> +++ b/drivers/mtd/spi-nor/spi-nor.c
>> @@ -485,6 +485,7 @@ static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
>>       u8 status_old, status_new;
>>       u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
>>       u8 shift = ffs(mask) - 1, pow, val;
>> +     int ret;
>
> I've merged other patches in the meantime (sorry), so this might need a
> rebasing on l2-mtd.git. I'd do it, but should get a v2 anyway.
>

No problem.

>>
>>       status_old = read_sr(nor);
>>
>> @@ -521,7 +522,13 @@ static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
>>               return -EINVAL;
>>
>>       write_enable(nor);
>> -     return write_sr(nor, status_new);
>> +     ret = write_sr(nor, status_new);
>> +     if (ret)
>> +             return ret;
>> +     ret = spi_nor_wait_till_ready(nor);
>> +     if (ret)
>> +             return ret;
>> +     return 0;
>
> Why not just return spi_nor_wait_till_ready(nor)?
>
>>  }
>>
>>  /*
>> @@ -535,6 +542,7 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
>>       uint8_t status_old, status_new;
>>       u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
>>       u8 shift = ffs(mask) - 1, pow, val;
>> +     int ret;
>>
>>       status_old = read_sr(nor);
>>
>> @@ -569,7 +577,13 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
>>               return -EINVAL;
>>
>>       write_enable(nor);
>> -     return write_sr(nor, status_new);
>> +     ret = write_sr(nor, status_new);
>> +     if (ret)
>> +             return ret;
>> +     ret = spi_nor_wait_till_ready(nor);
>> +     if (ret)
>> +             return ret;
>> +     return 0;
>
> Same?
>

Sure, somehow I missed that.

I'll send a fixed v2.
-- 
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar