Re: [RFC/RFT PATCH v1 9/9] mtd: spi: Skip reading the Serial Flash Discoverable Parameters

Lukasz Majewski
2018-09-29T20:57:50Z

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Hi Cyrille,

> Hi Lukasz,
>
> Le 27/09/2018 à 00:07, Lukasz Majewski a écrit :
> > The fsl-quadspi.c driver is not supporting SPINOR_OP_RDSFDP (0x5a)
> > read opcode - in the legacy driver we do read some garbage
> > data from AHB mapped area and then return on the first check
>
> If your controller reads garbage then spi_nor_parse_sfdp() fails and
> exists on the very first check: signature of the SFDP header. Hence
> everything should already go on as if the SPI_NOR_SKIP_SFDP flag is
> set.

Yes, this is the observed behaviour.

>
> So this patch doesn't change anything for your controller but
> prevents other controller from using QSPI protocols like SPI 1-4-4.
>
> This patch introduces a regression for other chips.

As stated in the patch series cover letter - this is to explicitly show
problems with qspi on vf610.

Thanks for your review.

>
> Best regards,
>
> Cyrille
>
> > (L2376 @ ./mtd/spi-nor/spi-nor.c)
> >
> > Signed-off-by: Lukasz Majewski <lukma@denx.de>
> > ---
> > drivers/mtd/spi-nor/spi-nor.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/mtd/spi-nor/spi-nor.c
> > b/drivers/mtd/spi-nor/spi-nor.c index 442102be174e..c79b8c33aeeb
> > 100644 --- a/drivers/mtd/spi-nor/spi-nor.c
> > +++ b/drivers/mtd/spi-nor/spi-nor.c
> > @@ -1103,7 +1103,7 @@ static const struct flash_info spi_nor_ids[]
> > = { { "n25q064", INFO(0x20ba17, 0, 64 * 1024, 128, SECT_4K |
> > SPI_NOR_QUAD_READ) }, { "n25q064a", INFO(0x20bb17, 0, 64 *
> > 1024, 128, SECT_4K | SPI_NOR_QUAD_READ) }, { "n25q128a11",
> > INFO(0x20bb18, 0, 64 * 1024, 256, SECT_4K | SPI_NOR_QUAD_READ) },
> > - { "n25q128a13", INFO(0x20ba18, 0, 64 * 1024, 256,
> > SECT_4K | SPI_NOR_QUAD_READ | SPI_NOR_DUAL_READ) },
> > + { "n25q128a13", INFO(0x20ba18, 0, 64 * 1024, 256,
> > SECT_4K | SPI_NOR_QUAD_READ | SPI_NOR_DUAL_READ |
> > SPI_NOR_SKIP_SFDP) }, { "n25q256a", INFO(0x20ba19, 0, 64 *
> > 1024, 512, SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> > { "n25q256ax1", INFO(0x20bb19, 0, 64 * 1024, 512, SECT_4K |
> > SPI_NOR_QUAD_READ) }, { "n25q512a", INFO(0x20bb20, 0, 64 * 1024,
> > 1024, SECT_4K | USE_FSR | SPI_NOR_QUAD_READ) },

Best regards,

Lukasz Majewski

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