Re: flash_lock issue for n25q 128mb spi nor part

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

On 03/12/2019 09:45, Tudor.Ambarus@microchip.com wrote:
> Hi, John,

Hi Tudor,

Thanks for getting back to me.

> 
> On 12/2/19 7:28 PM, John Garry wrote:
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>
>> Hi guys,
>>
>> I am testing the following driver on top of Linus' master branch with a
>> n25q128a11 part:
> 
> I understand the you enabled locking support for this flash on your side,
> because in mainline it is not yet there.
> 
> Be aware that this flash has BP3 support, and in mainline we support for now
> just BP0-BP2, so just a partial lock can be achieved, and it depends on what you
> tried to lock. It will be helpful to tell how you enabled the locking and what
> commands did you use.

So I am simply using flash_lock -l /dev/mtd0, which will try to lock the 
whole device. Now I see what you're saying about BP3 and how complete 
locking is not available.

> 
>>
>> https://lore.kernel.org/linux-mtd/1572886297-45400-3-git-send-email-john.garry@huawei.com/
>>
>> I am finding flash lock is not working. Even after a “successful” lock,
>> flash_lock is reporting flash is unlocked. And I can still write to the
>> flash.
>>
>> I find that since 39d1e3340c73 ("mtd: spi-nor: Fix clearing of QE bit on
>> lock()/unlock()"), we're using a 16b SR for this part in the driver, but
>> this part only has a 8b SR.
>>
>> This hack fixes the problem for me:
>>
>> @ -4691,7 +4691,7 @@ static void spi_nor_info_init_params(struct spi_nor
>> *nor)
>> params->set_4byte = spansion_set_4byte;
>> params->setup = spi_nor_default_setup;
>> /* Default to 16-bit Write Status (01h) Command */
>> - nor->flags |= SNOR_F_HAS_16BIT_SR;
>> +// nor->flags |= SNOR_F_HAS_16BIT_SR;
> 
> This means that bfpt is not parsed. You can confirm this by running with the
> patch from below.
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index f4afe123e9dc..735cd5202598 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -3545,8 +3545,11 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
>                  return err;
> 
>          /* Fix endianness of the BFPT DWORDs. */
> -       for (i = 0; i < BFPT_DWORD_MAX; i++)
> +       for (i = 0; i < BFPT_DWORD_MAX; i++) {
>                  bfpt.dwords[i] = le32_to_cpu(bfpt.dwords[i]);
> +               dev_err(nor->dev, "bfpt.dwords[%d] = %08x\n", i,
> +                       bfpt.dwords[i]);
> +       }
> 
>          /* Number of address bytes. */
>          switch (bfpt.dwords[BFPT_DWORD(1)] & BFPT_DWORD1_ADDRESS_BYTES_MASK) {
> @@ -3649,6 +3652,9 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
>          params->page_size >>= BFPT_DWORD11_PAGE_SIZE_SHIFT;
>          params->page_size = 1U << params->page_size;
> 
> +       dev_err(nor->dev, "bfpt.dwords[BFPT_DWORD(15)] & BFPT_DWORD15_QER_MASK =
> %08x\n",
> +               bfpt.dwords[BFPT_DWORD(15)] & BFPT_DWORD15_QER_MASK);
> +
>          /* Quad Enable Requirements. */
>          switch (bfpt.dwords[BFPT_DWORD(15)] & BFPT_DWORD15_QER_MASK) {
>          case BFPT_DWORD15_QER_NONE:
> 

john@ubuntu:~$ dmesg | grep spi
[   14.935740] spi-nor spi-PRP0001:00: bfpt.dwords[0] = fff920e5
[   14.941480] spi-nor spi-PRP0001:00: bfpt.dwords[1] = 07ffffff
[   14.947215] spi-nor spi-PRP0001:00: bfpt.dwords[2] = 6b27eb29
[   14.952949] spi-nor spi-PRP0001:00: bfpt.dwords[3] = bb273b27
[   14.958683] spi-nor spi-PRP0001:00: bfpt.dwords[4] = ffffffff
[   14.964417] spi-nor spi-PRP0001:00: bfpt.dwords[5] = bb27ffff
[   14.970150] spi-nor spi-PRP0001:00: bfpt.dwords[6] = eb29ffff
[   14.975884] spi-nor spi-PRP0001:00: bfpt.dwords[7] = d810200c
[   14.981618] spi-nor spi-PRP0001:00: bfpt.dwords[8] = 0000520f
[   14.987351] spi-nor spi-PRP0001:00: bfpt.dwords[9] = 00994a24
[   14.993085] spi-nor spi-PRP0001:00: bfpt.dwords[10] = c9038e8b
[   14.998906] spi-nor spi-PRP0001:00: bfpt.dwords[11] = 382701ac
[   15.004726] spi-nor spi-PRP0001:00: bfpt.dwords[12] = 757a757a
[   15.010547] spi-nor spi-PRP0001:00: bfpt.dwords[13] = 5cd5bdfb
[   15.016367] spi-nor spi-PRP0001:00: bfpt.dwords[14] = ff820f4a
[   15.022187] spi-nor spi-PRP0001:00: bfpt.dwords[15] = 00003d81

Thanks,
John


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