[U-Boot] U-boot: Erase/read/write issue with S25fl256S flash device

[Sourav Poddar]

Hi Jagan,
On Friday 14 June 2013 08:08 PM, Jagan Teki wrote:
> On 14-06-2013 20:03, Sourav Poddar wrote:
>>
>> Hi,
>>
>> On Wednesday 12 June 2013 01:00 PM, Sourav Poddar wrote:
>>> Hi,
>>>
>>> I am working on qspi flash device S25FL256S at u-boot level. I am
>>> trying to
>>> make use of the existing spi_flash.c framework available at u-boot for
>>> erasing/reading/writing
>>> into the flash device.
>>>
>>> There are several issues(mentioned below), which I faced while using
>>> S25FL256s flash device
>>> with my dra7xx board which has a qspi controller to which the above
>>> mentioned flash device is attached.
>>>
>>> 1. Erase (spi_flash_cmd_erase)
>>>
>>> Issuing a command something like this..
>>>
>>> sf erase 0x0 0x50000
>>>  - erases only first 0x20000 bytes of flash device, anything above
>>> that is not erase. I need to
>>>    issue separate commands after 0x20000 for every 0x10000 bytes.
>>>
>>> Am i missing anything here?
>>>
>>> 2. read
>>>
>>> sf read 81000000 0 0x10000
>>>
>>> Read is not happening properly. The last few byte along the 4k
>>> boundary always shows zero.
>>> Above 4k bytes, read is not happening.
>>>
>>> For ex:
>>>  DRA752 EVM # md 81000f00
>>> 81000f00: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000f10: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000f20: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000f30: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000f40: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000f50: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000f60: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000f70: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000f80: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000f90: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000fa0: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000fb0: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000fc0: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000fd0: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000fe0: ffffffff ffffffff ffffffff ffffffff    ................
>>> 81000ff0: ffffffff ffffffff 00ffffff 00000000    ................
>>>
>>> In this dump, if you see 81000ff0 the last column shows 000000 which is
>>> not expected. and it happens along every 4k bytes.
>>>
>>>
>>> So, to get rid of the above issue, I switched to page read with the
>>> below patch[1],
>>> which is giving me the correct result.
>>> [1]:
>>> @@ -147,17 +153,40 @@ int spi_flash_read_common(struct spi_flash
>>> *flash, const u8 *cmd,
>>>  int spi_flash_cmd_read_fast(struct spi_flash *flash, u32 offset,
>>>                 size_t len, void *data)
>>>  {
>>> -       u8 cmd[5];
>>> +       unsigned long page_addr, byte_addr, page_size;
>>> +       size_t chunk_len, actual;
>>> +       int ret = 0;
>>> +       u8 cmd[4];
>>>
>>>         /* Handle memory-mapped SPI */
>>>         if (flash->memory_map)
>>>                 memcpy(data, flash->memory_map + offset, len);
>>> +       page_size = flash->page_size;
>>> +       page_addr = offset / page_size;
>>> +       byte_addr = offset % page_size;
>>> +
>>> +       cmd[0] = CMD_READ_ARRAY_SLOW;
>>> +       for (actual = 0; actual < len; actual += chunk_len) {
>>> +               chunk_len = min(len - actual, page_size - byte_addr);
>>> +
>>> +               cmd[1] = page_addr >> 8;
>>> +               cmd[2] = page_addr;
>>> +               cmd[3] = byte_addr;
>>> +
>>> +               ret = spi_flash_read_common(flash, cmd, sizeof(cmd),
>>> data + actual, chunk_len);
>>> +               if (ret < 0) {
>>> +                       debug("SF: read failed");
>>> +                       break;
>>> +               }
>>>
>>> -       cmd[0] = CMD_READ_ARRAY_FAST;
>>> -       spi_flash_addr(offset, cmd);
>>> -       cmd[4] = 0x00;
>>> +               byte_addr += chunk_len;
>>> +               if (byte_addr == page_size) {
>>> +                       page_addr++;
>>> +                       byte_addr = 0;
>>> +               }
>>> +       }
>>>
>>> -       return spi_flash_read_common(flash, cmd, sizeof(cmd), data, 
>>> len);
>>> +       return ret;
>>>  }
>>>
>>> Any idea about this?
>>>
>>> 3.  write (spi_flash_cmd_write_multi)
>>>   write not happening properly.
>>>
>>> observations: only able to write single page, anything after a page is
>>> not getting
>>>         written.
>>> Workaround:
>>> I did a write disable latch at the end of every write cycle(page
>>> program) and enable it
>>> again for the next loop. With this, I see I get rid of the above issue.
>>>
>>>  @@ -117,6 +117,12 @@ int spi_flash_cmd_write_multi(struct spi_flash
>>> *flash, u32 offset,
>>>                 if (ret)
>>>                         break;
>>>
>>> +               ret = spi_flash_cmd_write_disable(flash);
>>> +               if (ret < 0) {
>>> +                       printf("SF: disabling write failed\n");
>>> +                       break;
>>> +               }
>>> +
>>>
>>>
>>> Have anyone seen the above mentioned issues regarding
>>> read/write/erase? OR is there any
>>> configurations that I might be missing ?
>>>
>> Any Input on this?
>
> Please wait, I am pushing some changes tonight or so.
>
> We will continue this thread, after testing your part with these new 
> changes.
>
> I will intimate you once the push done.
>
> -- 
> Thanks,
> Jagan.
>
>
Thanks a lot for the reply.
Sure, will wait for your changes to go in.

Thanks,
Sourav