Re: [PATCH v2] mtd: micron-st: enable lock/unlock for mt25qu512a

[Tudor Ambarus]

On 10/6/23 17:09, SHUKLA Mamta Ramendra wrote:
> 
> 
> Hello Tudor,
> 
Hi!

> 
>> On 10/6/23 14:33, Tudor Ambarus wrote:
>>>
>>> Hi,
>>>
>>> Thanks for the debugging info.
>>>
>>> On 10/6/23 11:30, SHUKLA Mamta Ramendra wrote:
>>>
>>> cut
>>>
>>>> --------------------------------------------------------
>>>>
>>>> IMO, HAS_16BIT_SR flag is causing lock/unlock failure,
>>>> since BP bits are calculated wrong then.
>>>>
>>>> I tested also for a case where I don't parse SFDP and
>>>> reverted the condition in  micron_st_nor_default_init()
>>>> for 16BIT Status Register Flag. And lock/unlock fails with
>>>> same log as Non-working case.
>>>>
>>>> And this mt25qu512 has 8-BIT SR as typical micron-st flash.
>>>>
>>>
>>> Indeed, the problem is that HAS_16BIT_SR gets set when it shouldn't have
>>> to. This means that the BFPT table of the flash is wrong and we should
>>> fix the parsed settings via a post_bfpt hook.
>>>
>>> Does the following fix your problem?
>>>
>>
>> here it is again, this time compile tested:
>>
>> diff --git a/drivers/mtd/spi-nor/micron-st.c
>> b/drivers/mtd/spi-nor/micron-st.c
>> index 4afcfc57c896..20f76e278095 100644
>> --- a/drivers/mtd/spi-nor/micron-st.c
>> +++ b/drivers/mtd/spi-nor/micron-st.c
>> @@ -180,6 +180,18 @@ static const struct flash_info micron_nor_parts[] = {
>>          },
>>   };
>>
>> +static int mt25qu512a_post_bfpt_fixup(struct spi_nor *nor,
>> +                               const struct sfdp_parameter_header
>> *bfpt_header,
>> +                               const struct sfdp_bfpt *bfpt)
>> +{
>> +       nor->flags &= ~SNOR_F_HAS_16BIT_SR;
>> +       return 0;
>> +}
>> +
>> +static struct spi_nor_fixups mt25qu512a_fixups = {
>> +       .post_bfpt = mt25qu512a_post_bfpt_fixup,
>> +};
>> +
>>   static const struct flash_info st_nor_parts[] = {
>>          {
>>                  .name = "m25p05-nonjedec",
>> @@ -405,10 +417,10 @@ static const struct flash_info st_nor_parts[] = {
>>          }, {
>>                  .id = SNOR_ID(0x20, 0xbb, 0x20, 0x10, 0x44, 0x00),
>>                  .name = "mt25qu512a",
>> -               .size = SZ_64M,
>> -               .no_sfdp_flags = SECT_4K | SPI_NOR_DUAL_READ |
>> SPI_NOR_QUAD_READ,
>> -               .fixup_flags = SPI_NOR_4B_OPCODES,
>> +               .flags = SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB |
>> SPI_NOR_4BIT_BP |
>> +                        SPI_NOR_BP3_SR_BIT6,
>>                  .mfr_flags = USE_FSR,
>> +               .fixups = &mt25qu512a_fixups,
>>          }, {
>>                  .id = SNOR_ID(0x20, 0xbb, 0x20),
>>                  .name = "n25q512a",
>>
>> cut
> 
> 
> Thanks. Yes, this post  BFPT fixup resolves lock/unlock issue and
> I don't see HAS_16BIT_SR flag in params.

Good. Please send some patches addressing all that we discussed until now.
> 
> 
> Datasheet is public: 
> https://media-www.micron.com/-/media/client/global/documents/products/data-sheet/nor-flash/serial-nor/mt25q/die-rev-b/mt25q_qlkt_u_512_abb_0.pdf?rev=b259aadc3bea49ea8210a41c9ad58211 
> 
I'll take a look later today.

Cheers,
ta
> 
>>> If yes, please add some prints in sfdp.c to determine where it's set,
>>> either in BFPT_DWORD15_QER_SR2_BIT1 or BFPT_DWORD15_QER_SR2_BIT1_NO_RD
>>> Is the datasheet for this flash public? Would you send me a link to it
>>> please?
>>>
>>> Cheers,
>>> ta