Re: [PATCH v2 0/5] mtd: spi-nor: Add support for Octal 8D-8D-8D mode

[masonccyang]

Hi Pratyush,

> > On Tue, 21 Apr 2020 14:39:42 +0800
> > Mason Yang <masonccyang@xxxxxxxxxxx> wrote:
> > 
> > > Hello,
> > > 
> > > This is repost of patchset from Boris Brezillon's
> > > [RFC,00/18] mtd: spi-nor: Proposal for 8-8-8 mode support [1].
> > 
> > I only quickly went through the patches you sent and saying it's a
> > repost of the RFC is a bit of a lie. You completely ignored the state
> > tracking I was trying to do to avoid leaving the flash in 8D mode when
> > suspending/resetting the board, and I think that part is crucial. If I
> > remember correctly, we already had this discussion so I must say I'm a
> > bit disappointed.
> > 
> > Can you sync with Pratyush? I think his series [1] is better in that 
it
> > tries to restore the flash in single-SPI mode before suspend (it's
> > missing the shutdown case, but that can be easily added I think). Of
> > course that'd be even better to have proper state tracking at the SPI
> > NOR level.
> 
> Hi Mason,
> 
> I posted a re-roll of my series here [0]. Could you please base your 
> changes on top of it? Let me know if the series is missing something you 

> need.
> 
> [0]  
https://lore.kernel.org/linux-mtd/20200424184410.8578-1-p.yadav@xxxxxx/


Our mx25uw51245g supports BFPT DWORD-18,19 and 20 data and xSPI profile 
1.0,
and it comply with BFPT DWORD-19, octal mode enable sequences by write CFG 
Reg2 
with instruction 0x72. Therefore, I can't apply your patches.

I quickly went through your patches but can't reply them in each your 
patches.

i.e,.
1) [v4,03/16] spi: spi-mem: allow specifying a command's extension

-                                u8 opcode;
+                                u16 opcode;

big/little Endian issue, right? 
why not just u8 ext_opcode;
No any impact for exist code and actually only xSPI device use extension 
command.


2) [v4,08/16] mtd: spi-nor: parse xSPI Profile 1.0 table

need extract more data from xSPI profile 1.0 table and no other specific 
setting. 


3) [v4,11/16] mtd: spi-nor: enable octal DTR mode when possible

+static int spi_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
+{
+                int ret;
+
+                if (!nor->params->octal_dtr_enable)
+                                return 0;
+
+                if (!(spi_nor_get_protocol_width(nor->read_proto) == 8 ||
+                      spi_nor_get_protocol_width(nor->write_proto) == 8))
+                                return 0;
+
+                ret = nor->params->octal_dtr_enable(nor, enable);
+                if (ret)
+                                return ret;
+
+                if (enable)
+                                nor->reg_proto = SNOR_PROTO_8_8_8_DTR;
+                else
+                                nor->reg_proto = SNOR_PROTO_1_1_1;
+
+                return 0;
+}
+

it seems you enable device in Octal mode after SPI-NOR Framework is 
already
in Octal protocol.
Driver should set device by SPI 1-1-1 mode to enter Octal mode and then 
setup
Read/PP command and protocol by spi_nor_set_read/pp_setting() for Octal 
mode,
right ?


thanks & best regards,
Mason



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