FAILED: patch "[PATCH] mtd: spi-nor: sst: Fix write enable before AAI sequence" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] mtd: spi-nor: sst: Fix write enable before AAI sequence" failed to apply to 6.6-stable tree

[gregkh]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x a0f64241d3566a49c0a9b33ba7ae458ae22003a9
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026050405-manly-surplus-9d27@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a0f64241d3566a49c0a9b33ba7ae458ae22003a9 Mon Sep 17 00:00:00 2001
From: Sanjaikumar V S <sanjaikumar.vs@dicortech.com>
Date: Wed, 11 Mar 2026 10:30:56 +0000
Subject: [PATCH] mtd: spi-nor: sst: Fix write enable before AAI sequence

When writing to SST flash starting at an odd address, a single byte is
first programmed using the byte program (BP) command. After this
operation completes, the flash hardware automatically clears the Write
Enable Latch (WEL) bit.

If an AAI (Auto Address Increment) word program sequence follows, it
requires WEL to be set. Without re-enabling writes, the AAI sequence
fails.

Add spi_nor_write_enable() after the odd-address byte program when more
data needs to be written. Use a local boolean for clarity.

Fixes: b199489d37b2 ("mtd: spi-nor: add the framework for SPI NOR")
Cc: stable@vger.kernel.org
Signed-off-by: Sanjaikumar V S <sanjaikumar.vs@dicortech.com>
Tested-by: Hendrik Donner <hd@os-cillation.de>
Reviewed-by: Hendrik Donner <hd@os-cillation.de>
Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>

diff --git a/drivers/mtd/spi-nor/sst.c b/drivers/mtd/spi-nor/sst.c
index 175211fe6a5e..db02c14ba16f 100644
--- a/drivers/mtd/spi-nor/sst.c
+++ b/drivers/mtd/spi-nor/sst.c
@@ -203,6 +203,8 @@ static int sst_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 
 	/* Start write from odd address. */
 	if (to % 2) {
+		bool needs_write_enable = (len > 1);
+
 		/* write one byte. */
 		ret = sst_nor_write_data(nor, to, 1, buf);
 		if (ret < 0)
@@ -210,6 +212,17 @@ static int sst_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 
 		to++;
 		actual++;
+
+		/*
+		 * Byte program clears the write enable latch. If more
+		 * data needs to be written using the AAI sequence,
+		 * re-enable writes.
+		 */
+		if (needs_write_enable) {
+			ret = spi_nor_write_enable(nor);
+			if (ret)
+				goto out;
+		}
 	}
 
 	/* Write out most of the data here. */

Re: FAILED: patch "[PATCH] mtd: spi-nor: sst: Fix write enable before AAI sequence" failed to apply to 6.6-stable tree

[Hendrik Donner]

Hello,

On 5/4/26 10:38, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 6.6-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
> 
> To reproduce the conflict and resubmit, you may use the following commands:
> 
> git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
> git checkout FETCH_HEAD
> git cherry-pick -x a0f64241d3566a49c0a9b33ba7ae458ae22003a9
> # <resolve conflicts, build, test, etc.>
> git commit -s
> git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026050405-manly-surplus-9d27@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
> 
> Possible dependencies:
> 
> 
> 
> thanks,
> 
> greg k-h
> 
> ------------------ original commit in Linus's tree ------------------
> 
>  From a0f64241d3566a49c0a9b33ba7ae458ae22003a9 Mon Sep 17 00:00:00 2001
> From: Sanjaikumar V S <sanjaikumar.vs@dicortech.com>
> Date: Wed, 11 Mar 2026 10:30:56 +0000
> Subject: [PATCH] mtd: spi-nor: sst: Fix write enable before AAI sequence
> 
> When writing to SST flash starting at an odd address, a single byte is
> first programmed using the byte program (BP) command. After this
> operation completes, the flash hardware automatically clears the Write
> Enable Latch (WEL) bit.
> 
> If an AAI (Auto Address Increment) word program sequence follows, it
> requires WEL to be set. Without re-enabling writes, the AAI sequence
> fails.
> 
> Add spi_nor_write_enable() after the odd-address byte program when more
> data needs to be written. Use a local boolean for clarity.
> 
> Fixes: b199489d37b2 ("mtd: spi-nor: add the framework for SPI NOR")
> Cc: stable@vger.kernel.org
> Signed-off-by: Sanjaikumar V S <sanjaikumar.vs@dicortech.com>
> Tested-by: Hendrik Donner <hd@os-cillation.de>
> Reviewed-by: Hendrik Donner <hd@os-cillation.de>
> Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
> 
> diff --git a/drivers/mtd/spi-nor/sst.c b/drivers/mtd/spi-nor/sst.c
> index 175211fe6a5e..db02c14ba16f 100644
> --- a/drivers/mtd/spi-nor/sst.c
> +++ b/drivers/mtd/spi-nor/sst.c
> @@ -203,6 +203,8 @@ static int sst_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
>   
>   	/* Start write from odd address. */
>   	if (to % 2) {
> +		bool needs_write_enable = (len > 1);
> +
>   		/* write one byte. */
>   		ret = sst_nor_write_data(nor, to, 1, buf);
>   		if (ret < 0)
> @@ -210,6 +212,17 @@ static int sst_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
>   
>   		to++;
>   		actual++;
> +
> +		/*
> +		 * Byte program clears the write enable latch. If more
> +		 * data needs to be written using the AAI sequence,
> +		 * re-enable writes.
> +		 */
> +		if (needs_write_enable) {
> +			ret = spi_nor_write_enable(nor);
> +			if (ret)
> +				goto out;
> +		}
>   	}
>   
>   	/* Write out most of the data here. */
> 

it doesn't apply because of changes made in
18bcb4aa54eab75dce41e5c176a1c2bff94f0f79.

That commit was never backported and is not in any stable tree older
than 6.12.y. So it needs to be applied first to 5.10.y, 5.15.y, 6.1.y
and 6.6.y. It's a refactor commit that should not change behaviour at all.

If that's not possible for some reason the conflict resolution looks
easy enough. I have something i can send out for review if needed.

Regards,
Hendrik

Re: FAILED: patch "[PATCH] mtd: spi-nor: sst: Fix write enable before AAI sequence" failed to apply to 6.6-stable tree

[Greg KH]

On Thu, May 07, 2026 at 07:31:43PM +0200, Hendrik Donner wrote:
> Hello,
> 
> On 5/4/26 10:38, gregkh@linuxfoundation.org wrote:
> > 
> > The patch below does not apply to the 6.6-stable tree.
> > If someone wants it applied there, or to any other stable or longterm
> > tree, then please email the backport, including the original git commit
> > id to <stable@vger.kernel.org>.
> > 
> > To reproduce the conflict and resubmit, you may use the following commands:
> > 
> > git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
> > git checkout FETCH_HEAD
> > git cherry-pick -x a0f64241d3566a49c0a9b33ba7ae458ae22003a9
> > # <resolve conflicts, build, test, etc.>
> > git commit -s
> > git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026050405-manly-surplus-9d27@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
> > 
> > Possible dependencies:
> > 
> > 
> > 
> > thanks,
> > 
> > greg k-h
> > 
> > ------------------ original commit in Linus's tree ------------------
> > 
> >  From a0f64241d3566a49c0a9b33ba7ae458ae22003a9 Mon Sep 17 00:00:00 2001
> > From: Sanjaikumar V S <sanjaikumar.vs@dicortech.com>
> > Date: Wed, 11 Mar 2026 10:30:56 +0000
> > Subject: [PATCH] mtd: spi-nor: sst: Fix write enable before AAI sequence
> > 
> > When writing to SST flash starting at an odd address, a single byte is
> > first programmed using the byte program (BP) command. After this
> > operation completes, the flash hardware automatically clears the Write
> > Enable Latch (WEL) bit.
> > 
> > If an AAI (Auto Address Increment) word program sequence follows, it
> > requires WEL to be set. Without re-enabling writes, the AAI sequence
> > fails.
> > 
> > Add spi_nor_write_enable() after the odd-address byte program when more
> > data needs to be written. Use a local boolean for clarity.
> > 
> > Fixes: b199489d37b2 ("mtd: spi-nor: add the framework for SPI NOR")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Sanjaikumar V S <sanjaikumar.vs@dicortech.com>
> > Tested-by: Hendrik Donner <hd@os-cillation.de>
> > Reviewed-by: Hendrik Donner <hd@os-cillation.de>
> > Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
> > 
> > diff --git a/drivers/mtd/spi-nor/sst.c b/drivers/mtd/spi-nor/sst.c
> > index 175211fe6a5e..db02c14ba16f 100644
> > --- a/drivers/mtd/spi-nor/sst.c
> > +++ b/drivers/mtd/spi-nor/sst.c
> > @@ -203,6 +203,8 @@ static int sst_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
> >   	/* Start write from odd address. */
> >   	if (to % 2) {
> > +		bool needs_write_enable = (len > 1);
> > +
> >   		/* write one byte. */
> >   		ret = sst_nor_write_data(nor, to, 1, buf);
> >   		if (ret < 0)
> > @@ -210,6 +212,17 @@ static int sst_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
> >   		to++;
> >   		actual++;
> > +
> > +		/*
> > +		 * Byte program clears the write enable latch. If more
> > +		 * data needs to be written using the AAI sequence,
> > +		 * re-enable writes.
> > +		 */
> > +		if (needs_write_enable) {
> > +			ret = spi_nor_write_enable(nor);
> > +			if (ret)
> > +				goto out;
> > +		}
> >   	}
> >   	/* Write out most of the data here. */
> > 
> 
> it doesn't apply because of changes made in
> 18bcb4aa54eab75dce41e5c176a1c2bff94f0f79.
> 
> That commit was never backported and is not in any stable tree older
> than 6.12.y. So it needs to be applied first to 5.10.y, 5.15.y, 6.1.y
> and 6.6.y. It's a refactor commit that should not change behaviour at all.

The refactor commit worked for 6.1.y and 6.6.y, but not the others.

thanks,

greg k-h