Re: [PATCH v2] mtd: spi-nor: micron-st: add SNOR_CMD_PP_8_8_8_DTR sfdp fixup for mt35xu512aba

From: Pratyush Yadav <pratyush@kernel.org>
To: Haibo Chen <haibo.chen@nxp.com>
Cc: Tudor Ambarus <tudor.ambarus@linaro.org>,
	 Pratyush Yadav <pratyush@kernel.org>,
	 Michael Walle <mwalle@kernel.org>,
	 Miquel Raynal <miquel.raynal@bootlin.com>,
	 Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	 linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
	 han.xu@nxp.com,  imx@lists.linux.dev
Subject: Re: [PATCH v2] mtd: spi-nor: micron-st: add SNOR_CMD_PP_8_8_8_DTR sfdp fixup for mt35xu512aba
Date: Tue, 23 Dec 2025 00:39:37 +0900	[thread overview]
Message-ID: <86fr92cypy.fsf@kernel.org> (raw)
In-Reply-To: <20251215-nor-v2-1-e75c0451e597@nxp.com> (Haibo Chen's message of "Mon, 15 Dec 2025 18:04:36 +0800")

On Mon, Dec 15 2025, Haibo Chen wrote:

> Find two batches mt35xu512aba has different SFDP but with same
> jedec ID. The batch which use the new version of SFDP contain
> all the necessary information to support OCT DTR mode. The batch
> with old version do not contain the OCT DTR command information,
> but in fact it did support OCT DTR mode.
>
> Current mt35xu512aba_post_sfdp_fixup() add some setting including
> SNOR_CMD_READ_8_8_8_DTR, but still lack SNOR_CMD_PP_8_8_8_DTR. Meet
> issue on the batch mt35xu512aba with old SFDP version. Because no
> SNOR_CMD_PP_8_8_8_DTR, micron_st_nor_octal_dtr_en() will not be
> called, then use SNOR_CMD_READ_8_8_8_DTR will meet issue.
>
> Fixes: 44dd635cd632 ("mtd: spi-nor: micron-st: use SFDP of mt35xu512aba")
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
> ---
> Changes in v2:
> - add 8D pp command in post sfdp fix up for the chip with old SFDP
> - Link to v1: https://lore.kernel.org/r/20251212-nor-v1-1-20a5a381979c@nxp.com
> ---
[...]
> ---
>  drivers/mtd/spi-nor/micron-st.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/mtd/spi-nor/micron-st.c b/drivers/mtd/spi-nor/micron-st.c
> index 88033384a71e5d19f5a26ca91f56a49e3017183a..5797bb748be696b340ff1398155f5ac8b1f74055 100644
> --- a/drivers/mtd/spi-nor/micron-st.c
> +++ b/drivers/mtd/spi-nor/micron-st.c
> @@ -167,6 +167,10 @@ static int mt35xu512aba_post_sfdp_fixup(struct spi_nor *nor)
>  				  0, 20, SPINOR_OP_MT_DTR_RD,
>  				  SNOR_PROTO_8_8_8_DTR);
>  

Please also add a comment here explaining why this fixup is needed, as
Michael suggested in v1. Probably a shorter version of the explanation
in the commit message.

With that, feel free to add:

Reviewed-by: Pratyush Yadav <pratyush@kernel.org>

> +	nor->params->hwcaps.mask |= SNOR_HWCAPS_PP_8_8_8_DTR;
> +	spi_nor_set_pp_settings(&nor->params->page_programs[SNOR_CMD_PP_8_8_8_DTR],
> +				SPINOR_OP_PP_4B, SNOR_PROTO_8_8_8_DTR);
> +
>  	nor->cmd_ext_type = SPI_NOR_EXT_REPEAT;
>  	nor->params->rdsr_dummy = 8;
>  	nor->params->rdsr_addr_nbytes = 0;
>
> ---
> base-commit: 4a5663c04bb679631985a15efab774da58c37815
> change-id: 20251212-nor-2f37cf12eeca
>
> Best regards,

-- 
Regards,
Pratyush Yadav

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