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

[Jagan Teki]

Hi Bin,

On 22 April 2015 at 14:13, Bin Meng <bmeng.cn at gmail.com> wrote:
> 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.
>

Worked on too-many overclocked issue, sorry for that.

So, something fixed in sf_probe.c will fix this I guess.

> => 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

thanks!
-- 
Jagan.