[PATCH v5] mtd: spi-nor: Fix SST AAI write mode opcode handling

[Hendrik Donner]

Hello,

On 3/31/26 11:50, Sanjaikumar V S wrote:
> From: Sanjaikumar V S <sanjaikumar.vs at dicortech.com>
> 
> When the SPI controller lacks direct mapping support, the fallback path
> in spi_nor_spimem_write_data() uses nor->write_proto based operation
> template. However, this template uses the standard page program opcode
> set during probe, not the AAI opcode required for SST flash.
> 
> Additionally, controllers that do support direct mapping will also use
> the wrong opcode since the dirmap template is created at probe time
> with the standard page program opcode.
> 
> Fix this by:
> 1. Checking the nodirmap flag in spi_nor_spimem_write_data() to ensure
>     the code falls through to spi_nor_spimem_exec_op() path which builds
>     the operation at runtime with the correct program_opcode.
> 2. Setting nodirmap=true for SST AAI devices in sst_nor_late_init() to
>     disable dirmap and force the runtime opcode path.
> 
> This only affects SST devices with SST_WRITE flag. Other SST devices
> that use standard page program can still benefit from dirmap.
> 
> Fixes: df5c21002cf4 ("mtd: spi-nor: use spi-mem dirmap API")
> Cc: stable at vger.kernel.org
> Signed-off-by: Sanjaikumar V S <sanjaikumar.vs at dicortech.com>
> ---
> Changes since v4:
> - Disable dirmap for SST AAI devices in sst_nor_late_init() to fix
>    the case when controller supports direct mapping (Pratyush)
> - Updated commit message and subject to reflect the broader fix
> 
> Note: Patch 1/2 from v4 series is already in spi-nor/next.
> 
> I don't have hardware to test the new sst.c change. Hendrik, could you
> please verify this on your SST25VF032B setup?
> 

retested, works the same as v4 on the SST25VF032B, don't have other SST
flashes at hand to test though.

Tested-by: Hendrik Donner <hd at os-cillation.de>
Reviewed-by: Hendrik Donner <hd at os-cillation.de>

Regards,
Hendrik

>   drivers/mtd/spi-nor/core.c |  2 +-
>   drivers/mtd/spi-nor/sst.c  | 10 +++++++++-
>   2 files changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index e6c1fda61f57..2e4b167cab57 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -281,7 +281,7 @@ static ssize_t spi_nor_spimem_write_data(struct spi_nor *nor, loff_t to,
>   	if (spi_nor_spimem_bounce(nor, &op))
>   		memcpy(nor->bouncebuf, buf, op.data.nbytes);
>   
> -	if (nor->dirmap.wdesc) {
> +	if (nor->dirmap.wdesc && !nor->dirmap.wdesc->nodirmap) {
>   		nbytes = spi_mem_dirmap_write(nor->dirmap.wdesc, op.addr.val,
>   					      op.data.nbytes, op.data.buf.out);
>   	} else {
> diff --git a/drivers/mtd/spi-nor/sst.c b/drivers/mtd/spi-nor/sst.c
> index db02c14ba16f..cd2f04830a6b 100644
> --- a/drivers/mtd/spi-nor/sst.c
> +++ b/drivers/mtd/spi-nor/sst.c
> @@ -267,8 +267,16 @@ static int sst_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
>   
>   static int sst_nor_late_init(struct spi_nor *nor)
>   {
> -	if (nor->info->mfr_flags & SST_WRITE)
> +	if (nor->info->mfr_flags & SST_WRITE) {
>   		nor->mtd._write = sst_nor_write;
> +		/*
> +		 * AAI mode requires dynamic opcode changes (BP vs AAI_WP).
> +		 * Disable dirmap to ensure spi_nor_spimem_exec_op() uses
> +		 * the runtime opcode instead of the dirmap template.
> +		 */
> +		if (nor->dirmap.wdesc)
> +			nor->dirmap.wdesc->nodirmap = true;
> +	}
>   
>   	return 0;
>   }