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

[Jagan Teki <jagannadh.teki@gmail.com>]

On 14-06-2013 20:13, Sourav Poddar wrote:
> 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.

Will take some time go these changes on master.

Please checkout master-work branch in u-boot-spi repo
git://git.denx.de/u-boot-spi.git

and try to test 256S parts, fyi: I tested the same part got the
+ve result.

--
Thanks,
Jagan.