[U-Boot] [EXT] [PATCH 2/2] spi-nor: spi-nor-ids: Disable SPI_NOR_4B_OPCODES for n25q512* and n25q256*

[Ashish Kumar <ashish.kumar@nxp.com>]

> -----Original Message-----
> From: Vignesh Raghavendra <vigneshr@ti.com>
> Sent: Wednesday, September 11, 2019 3:37 PM
> To: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>; Ashish Kumar
> <ashish.kumar@nxp.com>
> Cc: Jagan Teki <jagan@openedev.com>; u-boot at lists.denx.de;
> Alexey.Brodkin at synopsys.com; Eugeniy Paltsev
> <Eugeniy.Paltsev@synopsys.com>; Tom Rini <trini@konsulko.com>
> Subject: Re: [U-Boot] [EXT] [PATCH 2/2] spi-nor: spi-nor-ids: Disable
> SPI_NOR_4B_OPCODES for n25q512* and n25q256*
> 
> Caution: EXT Email
> 
> Hi Ashish, Simon,
> 
> On 11/09/19 3:11 PM, Simon Goldschmidt wrote:
> >
> >
> > Ashish Kumar <ashish.kumar at nxp.com <mailto:ashish.kumar@nxp.com>>
> > schrieb am Mi., 11. Sep. 2019, 10:49:
> >
> >
> >
> >     > -----Original Message-----
> >     > From: Vignesh Raghavendra <vigneshr@ti.com
> <mailto:vigneshr@ti.com>>
> >     > Sent: Tuesday, September 10, 2019 10:36 PM
> >     > To: Jagan Teki <jagan@openedev.com
> <mailto:jagan@openedev.com>>
> >     > Cc: Vignesh Raghavendra <vigneshr@ti.com
> >     <mailto:vigneshr@ti.com>>; u-boot at lists.denx.de
> >     <mailto:u-boot@lists.denx.de>; Tom
> >     > Rini <trini at konsulko.com <mailto:trini@konsulko.com>>; Eugeniy
> Paltsev
> >     > <Eugeniy.Paltsev@synopsys.com
> >     <mailto:Eugeniy.Paltsev@synopsys.com>>;
> Alexey.Brodkin at synopsys.com
> >     <mailto:Alexey.Brodkin@synopsys.com>; Ashish
> >     > Kumar <ashish.kumar at nxp.com <mailto:ashish.kumar@nxp.com>>
> >     > Subject: [EXT] [PATCH 2/2] spi-nor: spi-nor-ids: Disable
> >     > SPI_NOR_4B_OPCODES for n25q512* and n25q256*
> >     >
> >     > Caution: EXT Email
> >     >
> >     > Not all variants of n25q256* and n25q512* support 4 Byte stateless
> >     > addressing opcodes and there is no easy way to discover at runtime
> >     whether
> >     > the flash supports this feature or not.
> >     > Therefore don't set SPI_NOR_4B_OPCODES for these flashes.
> >     Hi Vignesh,
> >
> >     I think it will be good to keep it here and disable this for boards
> >     by using not set flag in config
> >     Like
> >     # SPI_NOR_4B_OPCODES is not set
> >
> 
> SPI_NOR_4B_OPCODES is not a config option. Are you suggesting to add
> one? config options don't scale well especially when same defconfig is used
> for multiple boards that potentially have different flashes
> 
> >
> > I'd prefer to take this patch, as this is what Linux does.
> 
> No, this is not what Linux does. There is no opt-in or opt-out option.
> Decision to use 4 byte opcode is done at runtime based on flash that's
> detected. Either based on info->flags for that part or by parsing SFDP table.
> There is no config option of DT option to force 4 byte addressing
> 
> > I think it's better to have an opt-in option. That way, all chips work
> > with the default settings (even if that means some chips don't use 4
> > baste opcodes even if they could).
> >
> 
> One solution would be to look at SFDP tables of two variants of flash and see
> if there are any differences that can be used as a clue.
> 
> Simon,
> Could you provide dump of SFDP tables and all the 6 bytes READ ID of the
> flash that you have?
> 
> I have asked Eugeniy to provide dumps from his flash on the other thread.
> Lets see if something stands out.
Hi Vignesh, Eugeniy,

Could you please provide me dump for n25q512a which consists of all 6 JEDEC id bytes.
I had initiated mail chain with MICRON FAE, and they suggest that extended id may be different for
n25q512a  from mt25qu512a.

I have dumped JEDEC ID from mt25qu512a "20, bb, 20, 10, 44, 00" , the second last byte is supposed to be different as per FAE.

Bit 6 
device
Generation
1 = 2nd
generation

Regards
Ashish 
> 
> Regards
> Vignesh
> 
> > Still, so we have such an op-in possibility to enable 4 byte opcodes
> > on these chips?
> >
> > Regards,
> > Simon
> >
> >
> >     Regards
> >     Ashish
> >     >
> >     > Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com
> >     <mailto:vigneshr@ti.com>> For n25q512ax3:
> >     > Tested-by: Eugeniy Paltsev <paltsev@synopsys.com
> >     <mailto:paltsev@synopsys.com>>
> >     > ---
> >     >  drivers/mtd/spi/spi-nor-ids.c | 6 +++---
> >     >  1 file changed, 3 insertions(+), 3 deletions(-)
> >     >
> >     > diff --git a/drivers/mtd/spi/spi-nor-ids.c
> >     b/drivers/mtd/spi/spi-nor-ids.c
> >     > index f32a6c7d464b..5a7fe07c8309 100644
> >     > --- a/drivers/mtd/spi/spi-nor-ids.c
> >     > +++ b/drivers/mtd/spi/spi-nor-ids.c
> >     > @@ -161,10 +161,10 @@ const struct flash_info spi_nor_ids[] = {
> >     >         { INFO("n25q064a",    0x20bb17, 0, 64 * 1024,  128, SECT_4K |
> >     > SPI_NOR_QUAD_READ) },
> >     >         { INFO("n25q128a11",  0x20bb18, 0, 64 * 1024,  256, SECT_4K |
> >     > SPI_NOR_QUAD_READ) },
> >     >         { INFO("n25q128a13",  0x20ba18, 0, 64 * 1024,  256, SECT_4K |
> >     > SPI_NOR_QUAD_READ) },
> >     > -       { INFO("n25q256a",    0x20ba19, 0, 64 * 1024,  512, SECT_4K |
> >     > SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
> SPI_NOR_4B_OPCODES) },
> >     > +       { INFO("n25q256a",    0x20ba19, 0, 64 * 1024,  512, SECT_4K |
> >     > SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> >     >         { INFO("n25q256ax1",  0x20bb19, 0, 64 * 1024,  512, SECT_4K |
> >     > SPI_NOR_QUAD_READ | SPI_NOR_4B_OPCODES) },
> >     > -       { INFO("mt25qu512a (n25q512a)",    0x20bb20, 0, 64 * 1024,
> >     1024,
> >     > SECT_4K | USE_FSR | SPI_NOR_QUAD_READ |
> SPI_NOR_4B_OPCODES) },
> >     > -       { INFO("n25q512ax3",  0x20ba20, 0, 64 * 1024, 1024,
> >     SECT_4K | USE_FSR |
> >     > SPI_NOR_QUAD_READ | SPI_NOR_4B_OPCODES) },
> >     > +       { INFO("mt25qu512a (n25q512a)",    0x20bb20, 0, 64 * 1024,
> >     1024,
> >     > SECT_4K | USE_FSR | SPI_NOR_QUAD_READ) },
> >     > +       { INFO("n25q512ax3",  0x20ba20, 0, 64 * 1024, 1024, SECT_4K |
> >     > + USE_FSR | SPI_NOR_QUAD_READ) },
> >     >         { INFO("n25q00",      0x20ba21, 0, 64 * 1024, 2048,
> >     SECT_4K | USE_FSR |
> >     > SPI_NOR_QUAD_READ | NO_CHIP_ERASE) },
> >     >         { INFO("n25q00a",     0x20bb21, 0, 64 * 1024, 2048,
> >     SECT_4K | USE_FSR |
> >     > SPI_NOR_QUAD_READ | NO_CHIP_ERASE) },
> >     >         { INFO("mt25qu02g",   0x20bb22, 0, 64 * 1024, 4096,
> >     SECT_4K | USE_FSR |
> >     > SPI_NOR_QUAD_READ | NO_CHIP_ERASE) },
> >     > --
> >     > 2.23.0
> >
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> --
> Regards
> Vignesh