Re: flash_lock issue for n25q 128mb spi nor part

[John Garry <john.garry@huawei.com>]

On 03/12/2019 12:27, Tudor.Ambarus@microchip.com wrote:
> 
> 
> On 12/3/19 2:05 PM, Tudor.Ambarus@microchip.com wrote:
>> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
>> index f4afe123e9dc..f1490c7b5cb9 100644
>> --- a/drivers/mtd/spi-nor/spi-nor.c
>> +++ b/drivers/mtd/spi-nor/spi-nor.c
>> @@ -1033,10 +1033,19 @@ static int spi_nor_write_16bit_sr_and_check(struct spi_nor *nor, u8 sr1)
>>
>>          sr_cr[0] = sr1;
>>
>> +       dev_err(nor->dev, "before write: sr_cr[0] = %02x, sr_cr[1] = %02x\n",
>> +               sr_cr[0], sr_cr[1]);
>> +
>>          ret = spi_nor_write_sr(nor, sr_cr, 2);
>>          if (ret)
>>                  return ret;
>>
>> +       ret = spi_nor_read_sr(nor, &sr_cr[0]);
>> +       if (ret)
>> +               return ret;
>> +
>> +       dev_err(nor->dev, "read back sr1: sr_cr[0] = %02x\n", sr_cr[0]);
>> +
>>          if (nor->flags & SNOR_F_NO_READ_CR)
>>                  return 0;
>>
>> @@ -1046,6 +1055,8 @@ static int spi_nor_write_16bit_sr_and_check(struct spi_nor *nor, u8 sr1)
>>          if (ret)
>>                  return ret;
>>
>> +       dev_err(nor->dev, "read back sr2: sr_cr[1] = %02x\n", sr_cr[1]);
>> +
>>          if (cr_written != sr_cr[1]) {
>>                  dev_dbg(nor->dev, "CR: read back test failed\
> 
> On n25q256a I obtain:
> 
> root@sama5d2-xplained-sd:~# flash_lock -l /dev/mtd1
> spi-nor spi1.0: before write: sr_cr[0] = 9e, sr_cr[1] = ff
> spi-nor spi1.0: read back sr1: sr_cr[0] = 02
> spi-nor spi1.0: read back sr2: sr_cr[1] = ff
> 

So here is what I get:

root@ubuntu:/home/john# flash_lock -l /dev/mtd0
[  109.037492] spi-nor spi-PRP0001:00: before write: sr_cr[0] = 9e, 
sr_cr[1] = 00
[  109.044769] spi-nor spi-PRP0001:00: read back sr1: sr_cr[0] = 02
[  109.050790] spi-nor spi-PRP0001:00: read back sr2: sr_cr[1] = 00


> the 16 bit write SR does not execute correctly and the WE remains set. If
> neither of the micron flashes do not support the 16 bit write SR, we can add a
> condition based on MFR. Let me check few datasheets.
> 

OK, thanks.

John


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/