linux-mtd.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
* Query Regarding NOR flash page size calculation s25fl512s
@ 2018-08-31  4:57 Yogesh Gaur
  2018-09-17 10:05 ` Yogesh Narayan Gaur
  0 siblings, 1 reply; 4+ messages in thread
From: Yogesh Gaur @ 2018-08-31  4:57 UTC (permalink / raw)
  To: linux-mtd

Hi All,

I have query and concern regarding page_size calculation for the
underlying NOR flashes.

I have spansion, ‘s25fl512s’ flash connected on my target.

With SFDP param reading, page_size for this flash is assigned as 0x200
using below routine.
   /* Page size: this field specifies 'N' so the page size = 2^N bytes. */
   params->page_size = bfpt.dwords[BFPT_DWORD(11)];
   params->page_size &= BFPT_DWORD11_PAGE_SIZE_MASK;
   params->page_size >>= BFPT_DWORD11_PAGE_SIZE_SHIFT;
   params->page_size = 1U << params->page_size;

As per the BG of S25FS512S_512_M flash and SFDP header info table
above calculation are correct.

But final value of the page_size for this flash is depends on the
configuration register CR3V[4], page buffer wrap, it can be either of
256 byte (0) or 512 byte (1).

For my case, this value is 0 and page_size becomes 0x100 bytes but
with SFDP header read, value for this is being assigned as 0x200.
Due to this, I am getting data corruption.

Please suggest, how can we check and proceed in these case. I guess
this is specific to spansion family of flashes.

IMO, for this flash we need to add flag SPI_NOR_SKIP_SFDP for entry of
this flash, s25fl512s.


Regards,
Yogesh

^ permalink raw reply	[flat|nested] 4+ messages in thread
* RE: Query Regarding NOR flash page size calculation s25fl512s
  2018-08-31  4:57 Query Regarding NOR flash page size calculation s25fl512s Yogesh Gaur
@ 2018-09-17 10:05 ` Yogesh Narayan Gaur
  2018-09-17 11:41   ` Boris Brezillon
  0 siblings, 1 reply; 4+ messages in thread
From: Yogesh Narayan Gaur @ 2018-09-17 10:05 UTC (permalink / raw)
  To: Yogesh Gaur, linux-mtd, Cyrille Pitchen, Boris Brezillon

Hi All,

Please suggest how can we work for this flash, s25fl512s?
Passing flag SPI_NOR_SKIP_SFDP would going to break functionality of 1-2-2/1-4-4 protocol mode, as only through SFDP parameter read we get information for the dummy cycles, mode bits etc for this flash.

But, page_size value is getting populated wrongly for case when value of CR3V[4] is 0 for this flash.

--
Regards
Yogesh Gaur

> -----Original Message-----
> From: linux-mtd [mailto:linux-mtd-bounces@lists.infradead.org] On Behalf Of
> Yogesh Gaur
> Sent: Friday, August 31, 2018 10:28 AM
> To: linux-mtd@lists.infradead.org
> Subject: Query Regarding NOR flash page size calculation s25fl512s
> 
> Hi All,
> 
> I have query and concern regarding page_size calculation for the underlying
> NOR flashes.
> 
> I have spansion, ‘s25fl512s’ flash connected on my target.
> 
> With SFDP param reading, page_size for this flash is assigned as 0x200 using
> below routine.
>    /* Page size: this field specifies 'N' so the page size = 2^N bytes. */
>    params->page_size = bfpt.dwords[BFPT_DWORD(11)];
>    params->page_size &= BFPT_DWORD11_PAGE_SIZE_MASK;
>    params->page_size >>= BFPT_DWORD11_PAGE_SIZE_SHIFT;
>    params->page_size = 1U << params->page_size;
> 
> As per the BG of S25FS512S_512_M flash and SFDP header info table above
> calculation are correct.
> 
> But final value of the page_size for this flash is depends on the configuration
> register CR3V[4], page buffer wrap, it can be either of
> 256 byte (0) or 512 byte (1).
> 
> For my case, this value is 0 and page_size becomes 0x100 bytes but with SFDP
> header read, value for this is being assigned as 0x200.
> Due to this, I am getting data corruption.
> 
> Please suggest, how can we check and proceed in these case. I guess this is
> specific to spansion family of flashes.
> 
> IMO, for this flash we need to add flag SPI_NOR_SKIP_SFDP for entry of this
> flash, s25fl512s.
> 
> 
> Regards,
> Yogesh
> 
> ______________________________________________________
> Linux MTD discussion mailing list
> https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.infr
> adead.org%2Fmailman%2Flistinfo%2Flinux-
> mtd%2F&amp;data=02%7C01%7Cyogeshnarayan.gaur%40nxp.com%7Cebe34d2
> 48bd54e4c399508d60efe5805%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%
> 7C0%7C636712882907344494&amp;sdata=m%2BtwKRbzFEYc2hqxUiloYT5SKGq
> eAkscVVPk7AkOaHM%3D&amp;reserved=0

^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: Query Regarding NOR flash page size calculation s25fl512s
  2018-09-17 10:05 ` Yogesh Narayan Gaur
@ 2018-09-17 11:41   ` Boris Brezillon
  2018-09-18 10:19     ` Cyrille Pitchen
  0 siblings, 1 reply; 4+ messages in thread
From: Boris Brezillon @ 2018-09-17 11:41 UTC (permalink / raw)
  To: Yogesh Narayan Gaur; +Cc: Yogesh Gaur, linux-mtd, Cyrille Pitchen, Marek Vasut

Hi Yogesh,

On Mon, 17 Sep 2018 10:05:27 +0000
Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com> wrote:

> Hi All,
> 
> Please suggest how can we work for this flash, s25fl512s?
> Passing flag SPI_NOR_SKIP_SFDP would going to break functionality of 1-2-2/1-4-4 protocol mode, as only through SFDP parameter read we get information for the dummy cycles, mode bits etc for this flash.
> 
> But, page_size value is getting populated wrongly for case when value of CR3V[4] is 0 for this flash.
> 
> --
> Regards
> Yogesh Gaur
> 
> > -----Original Message-----
> > From: linux-mtd [mailto:linux-mtd-bounces@lists.infradead.org] On Behalf Of
> > Yogesh Gaur
> > Sent: Friday, August 31, 2018 10:28 AM
> > To: linux-mtd@lists.infradead.org
> > Subject: Query Regarding NOR flash page size calculation s25fl512s
> > 
> > Hi All,
> > 
> > I have query and concern regarding page_size calculation for the underlying
> > NOR flashes.
> > 
> > I have spansion, ‘s25fl512s’ flash connected on my target.
> > 
> > With SFDP param reading, page_size for this flash is assigned as 0x200 using
> > below routine.
> >    /* Page size: this field specifies 'N' so the page size = 2^N bytes. */
> >    params->page_size = bfpt.dwords[BFPT_DWORD(11)];
> >    params->page_size &= BFPT_DWORD11_PAGE_SIZE_MASK;
> >    params->page_size >>= BFPT_DWORD11_PAGE_SIZE_SHIFT;
> >    params->page_size = 1U << params->page_size;
> > 
> > As per the BG of S25FS512S_512_M flash and SFDP header info table above
> > calculation are correct.
> > 
> > But final value of the page_size for this flash is depends on the configuration
> > register CR3V[4], page buffer wrap, it can be either of
> > 256 byte (0) or 512 byte (1).
> > 
> > For my case, this value is 0 and page_size becomes 0x100 bytes but with SFDP
> > header read, value for this is being assigned as 0x200.
> > Due to this, I am getting data corruption.
> > 
> > Please suggest, how can we check and proceed in these case. I guess this is
> > specific to spansion family of flashes.

I guess we need some kind of ->fixup() hook that the core would call
after SFDP has been parsed, so that vendors can adjust SPI NOR params.

Marek, Cyrille, any opinion on that?

Thanks,

Boris

^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: Query Regarding NOR flash page size calculation s25fl512s
  2018-09-17 11:41   ` Boris Brezillon
@ 2018-09-18 10:19     ` Cyrille Pitchen
  0 siblings, 0 replies; 4+ messages in thread
From: Cyrille Pitchen @ 2018-09-18 10:19 UTC (permalink / raw)
  To: Boris Brezillon, Yogesh Narayan Gaur
  Cc: Marek Vasut, Yogesh Gaur, Cyrille Pitchen, linux-mtd

Hi all,

Le 17/09/2018 à 13:41, Boris Brezillon a écrit :
> Hi Yogesh,
> 
> On Mon, 17 Sep 2018 10:05:27 +0000
> Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com> wrote:
> 
>> Hi All,
>>
>> Please suggest how can we work for this flash, s25fl512s?
>> Passing flag SPI_NOR_SKIP_SFDP would going to break functionality of 1-2-2/1-4-4 protocol mode, as only through SFDP parameter read we get information for the dummy cycles, mode bits etc for this flash.
>>
>> But, page_size value is getting populated wrongly for case when value of CR3V[4] is 0 for this flash.
>>
>> --
>> Regards
>> Yogesh Gaur
>>
>>> -----Original Message-----
>>> From: linux-mtd [mailto:linux-mtd-bounces@lists.infradead.org] On Behalf Of
>>> Yogesh Gaur
>>> Sent: Friday, August 31, 2018 10:28 AM
>>> To: linux-mtd@lists.infradead.org
>>> Subject: Query Regarding NOR flash page size calculation s25fl512s
>>>
>>> Hi All,
>>>
>>> I have query and concern regarding page_size calculation for the underlying
>>> NOR flashes.
>>>
>>> I have spansion, ‘s25fl512s’ flash connected on my target.
>>>
>>> With SFDP param reading, page_size for this flash is assigned as 0x200 using
>>> below routine.
>>>    /* Page size: this field specifies 'N' so the page size = 2^N bytes. */
>>>    params->page_size = bfpt.dwords[BFPT_DWORD(11)];
>>>    params->page_size &= BFPT_DWORD11_PAGE_SIZE_MASK;
>>>    params->page_size >>= BFPT_DWORD11_PAGE_SIZE_SHIFT;
>>>    params->page_size = 1U << params->page_size;
>>>
>>> As per the BG of S25FS512S_512_M flash and SFDP header info table above
>>> calculation are correct.
>>>
>>> But final value of the page_size for this flash is depends on the configuration
>>> register CR3V[4], page buffer wrap, it can be either of
>>> 256 byte (0) or 512 byte (1).
>>>
>>> For my case, this value is 0 and page_size becomes 0x100 bytes but with SFDP
>>> header read, value for this is being assigned as 0x200.
>>> Due to this, I am getting data corruption.
>>>
>>> Please suggest, how can we check and proceed in these case. I guess this is
>>> specific to spansion family of flashes.
> 
> I guess we need some kind of ->fixup() hook that the core would call
> after SFDP has been parsed, so that vendors can adjust SPI NOR params.
> 
> Marek, Cyrille, any opinion on that?
>

just few info that might be useful:

1 - Cypress S25FL512S:

JEDEC ID: 01 02 20 4D 00 80

5th byte: 00 - uniform 256-kB sectors
6th byte: 80 - Family ID - FL-S Family

- no Configuration Register 3
- page size is always 512 bytes
- SFDP compliant

2 - Cypress S25FS512S:

JEDEC ID: 01 02 20 4D 00 81
 
5th byte: 00 - uniform 256-kB sectors
6th byte: 81 - Family ID - S25FS512S

- has both Volatile and Non-Volatile Configuration Register 3 (Volatile CR3 reset
  value is Non-Volatile CR3 value), with bit4 Page Buffer Wrap.
  based on the datasheet the factory setting for CR3NV[4] is 0, hence 256-byte
  page size but SFDP table claims the page size is 512 byte... joy and happiness...
- page size depends on CR3V[4]: 0 -> 256 bytes, 1 -> 512 bytes
- SFDP compliant


Then few suggestions:

First, change the "s25fl512s" entry to use the INFO6() macro instead INFO().
Then create a new entry for "s25fs512s" entry also using INFO6()
Finally either:
A - you add the SPI_NOR_SKIP_SFDP flag on the new "s25fs512s" entry (clearly not my
  preferred solution).
B - set some ->fixup() hook, ass suggested by Boris, to the new "s25fs512s" entry
    only.

Solution A would introduce a regression for those already using the S25FS512S
memory part with the current "s25fl512s" entry in spi_nor_ids[].

Best regards,

Cyrille


> Thanks,
> 
> Boris
> 
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/
> 

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-09-18 10:19 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-08-31  4:57 Query Regarding NOR flash page size calculation s25fl512s Yogesh Gaur
2018-09-17 10:05 ` Yogesh Narayan Gaur
2018-09-17 11:41   ` Boris Brezillon
2018-09-18 10:19     ` Cyrille Pitchen

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).