[U-Boot] [PATCH v3 1/9] sf: Update SST flash params

[Bin Meng]

Hi Jagan,

On Wed, Apr 22, 2015 at 4:06 PM, Jagan Teki <jagannadh.teki at gmail.com> wrote:
> Hi Bin,
>
> On 22 April 2015 at 12:44, Bin Meng <bmeng.cn at gmail.com> wrote:
>> Hi Jagan,
>>
>> On Wed, Apr 22, 2015 at 3:03 PM, Jagan Teki <jagannadh.teki at gmail.com> wrote:
>>> Hi Bin,
>>>
>>> On 22 April 2015 at 12:14, Bin Meng <bmeng.cn at gmail.com> wrote:
>>>> Hi Jagan,
>>>>
>>>> On Tue, Apr 21, 2015 at 8:47 PM, Jagan Teki <jagannadh.teki at gmail.com> wrote:
>>>>> Hi Bin,
>>>>>
>>>>> On 20 April 2015 at 15:02, Bin Meng <bmeng.cn at gmail.com> wrote:
>>>>>> Hi Jagan,
>>>>>>
>>>>>> On Fri, Apr 17, 2015 at 4:48 PM, Jagan Teki <jagannadh.teki at gmail.com> wrote:
>>>>>>> Hi Bin,
>>>>>>>
>>>>>>> On 17 April 2015 at 07:14, Bin Meng <bmeng.cn at gmail.com> wrote:
>>>>>>>> Hi Jagan,
>>>>>>>>
>>>>>>>> On Fri, Apr 17, 2015 at 2:09 AM, Jagan Teki <jagannadh.teki at gmail.com> wrote:
>>>>>>>>> Hi Bin,
>>>>>>>>>
>>>>>>>>> I think you have a different interpretation of sector size here-
>>>>>>>>>
>>>>>>>>> /* The size listed here is what works with SPINOR_OP_SE, which isn't
>>>>>>>>>  * necessarily called a "sector" by the vendor.
>>>>>>>>>  */
>>>>>>>>> Say for example SST25VF040B has 8 sectors of which each sector size is
>>>>>>>>> 64 * 1024 out of this we can use 4K sector erase or 32K sector erase or
>>>>>>>>> 64K sector erase through flags.
>>>>>>>>>
>>>>>>>>> Linux does follow the same-
>>>>>>>>>         /* SST -- large erase sizes are "overlays", "sectors" are 4K */
>>>>>>>>>         { "sst25vf040b", INFO(0xbf258d, 0, 64 * 1024,  8, SECT_4K |
>>>>>>>>> SST_WRITE) },
>>>>>>>>>         { "sst25vf080b", INFO(0xbf258e, 0, 64 * 1024, 16, SECT_4K |
>>>>>>>>> SST_WRITE) },
>>>>>>>>>         { "sst25vf016b", INFO(0xbf2541, 0, 64 * 1024, 32, SECT_4K |
>>>>>>>>> SST_WRITE) },
>>>>>>>>>         { "sst25vf032b", INFO(0xbf254a, 0, 64 * 1024, 64, SECT_4K |
>>>>>>>>> SST_WRITE) },
>>>>>>>>>
>>>>>>>>> Please check it.
>>>>>>>>
>>>>>>>>
>>>>>>>> Yes, I know this pretty well. And I want to change this behavior, as
>>>>>>>> my cover letter says.
>>>>>>>>
>>>>>>>> Currently the 'sf erase' command operates on a 64KB granularity, while
>>>>>>>> the actual erase command is 4KB granularity, which is inconsistent and
>>>>>>>> causes confusion.
>>>>>>>
>>>>>>> It never related to 'sf erase' instead based on the 'params->flags'
>>>>>>> sf_probe will decide which erase_cmd with erase_size will use.
>>>>>>
>>>>>> No, it is related. See cmd_sf.c:
>>>>>
>>>>> I'm not getting your point- how could it erase use 64K sector size
>>>>> instead of 4K.
>>>>
>>>> It indeed erases 64K sector size. You need check the logic in
>>>> spi_flash_validate_params().
>>>
>>> We're assigning erase_size to sector_size only when SECT_4K and SECT_32K
>>> and for these erase_size becomes direct values, please check this.
>>
>> You previous email already said: the 'sf erase' command depends on
>> *flash->sector_size*
>>
>>>        /* Compute erase sector and command */
>>>         if (params->flags & SECT_4K) {
>>>                 flash->erase_cmd = CMD_ERASE_4K;
>>>                 flash->erase_size = 4096;
>>>         } else if (params->flags & SECT_32K) {
>>>                 flash->erase_cmd = CMD_ERASE_32K;
>>>                 flash->erase_size = 32768;
>>>         } else {
>>>                 flash->erase_cmd = CMD_ERASE_64K;
>>>                 flash->erase_size = flash->sector_size;
>>>         }
>>
>> Here the codes says: *flash->erase_size*
>>
>> So when I give a 'sf erase 0 100' it erase 64KB even if you have SECT_4K.
>
> Example:
> "SST25WF080",     0xbf2505, 0x0,       64 * 1024,    16, RD_NORM,
>     SECT_4K | SST_WR},
>
> sf probe gives
> sector_size = 64 * 1024 and erase_size = 4096
>
> sf erase 0 100
> sf_parse_len_arg len returns 100 and spi_flash_cmd_erase_ops returns
> "SF: Erase offset/length not multiple of erase size"

sf erase 0 +100. Sorry for the typo. But looks like you are not really
reading the codes.

=> sf probe
SF: Detected SST25VF016B with page size 256 Bytes, erase size 4 KiB,
total 2 MiB, mapped at ffe00000

=> sf erase 0 +100
SF: 65536 bytes @ 0x0 Erased: OK

Tested on two boards, and both shows 64K was erased.

> Example:
> "SST25WF080",     0xbf2505, 0x0,       64 * 1024,    16, RD_NORM,
>     SST_WR},
>
> sf probe gives
> sector_size = 64 * 1024 and erase_size = 64 * 1024
>
> sf erase 0 100
> sf_parse_len_arg len returns 100 and spi_flash_cmd_erase_ops returns
> "SF: Erase offset/length not multiple of erase size"
>
> Still have any concerns, please come to IRC for more discussion
>

Regards,
Bin