[PATCH] mtd: spi-nor: Unprepare legacy controllers upon RWW wait interruption

[PATCH] mtd: spi-nor: Unprepare legacy controllers upon RWW wait interruption

[Miquel Raynal]

All the parallel locking helpers (spi_nor_prep_and_lock(),
spi_nor_prep_and_lock_pe() and spi_nor_prep_and_lock_rd()) call
spi_nor_prep() then wait with a killable sleep. If the sleep gets
killed, we leave the controller in its prepared state.

Call ->unprepare() in these cases.

Fixes: 74df43b3f626 ("mtd: spi-nor: Enhance locking to support reads while writes")
Cc: stable@vger.kernel.org
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/mtd/spi-nor/core.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 8bc117b46e02..250e996284f9 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -1346,6 +1346,9 @@ int spi_nor_prep_and_lock(struct spi_nor *nor)
 		ret = wait_event_killable(nor->rww.wait,
 					  spi_nor_rww_start_exclusive(nor));
 
+	if (ret)
+		spi_nor_unprep(nor);
+
 	return ret;
 }
 
@@ -1417,6 +1420,9 @@ static int spi_nor_prep_and_lock_pe(struct spi_nor *nor, loff_t start, size_t le
 		ret = wait_event_killable(nor->rww.wait,
 					  spi_nor_rww_start_pe(nor, start, len));
 
+	if (ret)
+		spi_nor_unprep(nor);
+
 	return ret;
 }
 
@@ -1490,6 +1496,9 @@ static int spi_nor_prep_and_lock_rd(struct spi_nor *nor, loff_t start, size_t le
 		ret = wait_event_killable(nor->rww.wait,
 					  spi_nor_rww_start_rd(nor, start, len));
 
+	if (ret)
+		spi_nor_unprep(nor);
+
 	return ret;
 }
 

---
base-commit: db5f6418501f9795a96026b764d747179a231b2b
change-id: 20260811-perso-rww-fixes-016cdd229647

Best regards,
-- 
Miquel Raynal <miquel.raynal@bootlin.com>


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Re: [PATCH] mtd: spi-nor: Unprepare legacy controllers upon RWW wait interruption

[Michael Walle]

On Tue Aug 11, 2026 at 5:56 PM CEST, Miquel Raynal wrote:
> All the parallel locking helpers (spi_nor_prep_and_lock(),
> spi_nor_prep_and_lock_pe() and spi_nor_prep_and_lock_rd()) call
> spi_nor_prep() then wait with a killable sleep. If the sleep gets
> killed, we leave the controller in its prepared state.
>

Why does this only affect legacy controllers?

> Call ->unprepare() in these cases.
>
> Fixes: 74df43b3f626 ("mtd: spi-nor: Enhance locking to support reads while writes")
> Cc: stable@vger.kernel.org
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Reviewed-by: Michael Walle <mwalle@kernel.org>

-michael

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Re: [PATCH] mtd: spi-nor: Unprepare legacy controllers upon RWW wait interruption

[Miquel Raynal]

Hello,

> On Tue Aug 11, 2026 at 5:56 PM CEST, Miquel Raynal wrote:
>> All the parallel locking helpers (spi_nor_prep_and_lock(),
>> spi_nor_prep_and_lock_pe() and spi_nor_prep_and_lock_rd()) call
>> spi_nor_prep() then wait with a killable sleep. If the sleep gets
>> killed, we leave the controller in its prepared state.
>>
>
> Why does this only affect legacy controllers?

Aren't ->prepare()/->unprepare() callbacks only implemented by legacy
spi-nor controllers?

Thanks,
Miquèl

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Re: [PATCH] mtd: spi-nor: Unprepare legacy controllers upon RWW wait interruption

[Michael Walle]

On Wed Aug 12, 2026 at 12:05 PM CEST, Miquel Raynal wrote:
> Hello,
>
>> On Tue Aug 11, 2026 at 5:56 PM CEST, Miquel Raynal wrote:
>>> All the parallel locking helpers (spi_nor_prep_and_lock(),
>>> spi_nor_prep_and_lock_pe() and spi_nor_prep_and_lock_rd()) call
>>> spi_nor_prep() then wait with a killable sleep. If the sleep gets
>>> killed, we leave the controller in its prepared state.
>>>
>>
>> Why does this only affect legacy controllers?
>
> Aren't ->prepare()/->unprepare() callbacks only implemented by legacy
> spi-nor controllers?

ah ok :)

-michael

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Re: [PATCH] mtd: spi-nor: Unprepare legacy controllers upon RWW wait interruption

[Tudor Ambarus]

On 8/11/26 6:56 PM, Miquel Raynal wrote:
> All the parallel locking helpers (spi_nor_prep_and_lock(),
> spi_nor_prep_and_lock_pe() and spi_nor_prep_and_lock_rd()) call
> spi_nor_prep() then wait with a killable sleep. If the sleep gets
> killed, we leave the controller in its prepared state.
> 
> Call ->unprepare() in these cases.


We don't even care about SPI NOR controllers. I stopped adding/accepting
new support for them few years ago, so that we encourage people to update
the drivers to use SPI MEM.

The alternative is to drop prep unprep entirely.

Anyway, all good, regardless the path chosen:

Acked-by: Tudor Ambarus <tudor.ambarus@linaro.org>
> 
> Fixes: 74df43b3f626 ("mtd: spi-nor: Enhance locking to support reads while writes")
> Cc: stable@vger.kernel.org
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
>  drivers/mtd/spi-nor/core.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index 8bc117b46e02..250e996284f9 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -1346,6 +1346,9 @@ int spi_nor_prep_and_lock(struct spi_nor *nor)
>  		ret = wait_event_killable(nor->rww.wait,
>  					  spi_nor_rww_start_exclusive(nor));
>  
> +	if (ret)
> +		spi_nor_unprep(nor);
> +
>  	return ret;
>  }
>  
> @@ -1417,6 +1420,9 @@ static int spi_nor_prep_and_lock_pe(struct spi_nor *nor, loff_t start, size_t le
>  		ret = wait_event_killable(nor->rww.wait,
>  					  spi_nor_rww_start_pe(nor, start, len));
>  
> +	if (ret)
> +		spi_nor_unprep(nor);
> +
>  	return ret;
>  }
>  
> @@ -1490,6 +1496,9 @@ static int spi_nor_prep_and_lock_rd(struct spi_nor *nor, loff_t start, size_t le
>  		ret = wait_event_killable(nor->rww.wait,
>  					  spi_nor_rww_start_rd(nor, start, len));
>  
> +	if (ret)
> +		spi_nor_unprep(nor);
> +
>  	return ret;
>  }
>  
> 
> ---
> base-commit: db5f6418501f9795a96026b764d747179a231b2b
> change-id: 20260811-perso-rww-fixes-016cdd229647
> 
> Best regards,


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Re: [PATCH] mtd: spi-nor: Unprepare legacy controllers upon RWW wait interruption

[Miquel Raynal]

On 12/08/2026 at 12:52:48 +03, Tudor Ambarus <tudor.ambarus@linaro.org> wrote:

> On 8/11/26 6:56 PM, Miquel Raynal wrote:
>> All the parallel locking helpers (spi_nor_prep_and_lock(),
>> spi_nor_prep_and_lock_pe() and spi_nor_prep_and_lock_rd()) call
>> spi_nor_prep() then wait with a killable sleep. If the sleep gets
>> killed, we leave the controller in its prepared state.
>> 
>> Call ->unprepare() in these cases.
>
>
> We don't even care about SPI NOR controllers. I stopped adding/accepting
> new support for them few years ago, so that we encourage people to update
> the drivers to use SPI MEM.

Yeah, totally agreed.

> The alternative is to drop prep unprep entirely.

That's indeed what we aim for, but in order to "fix" that report, the
current solution is to call ->unprepare(). Hopefully we can remove them
at some point.

>
> Anyway, all good, regardless the path chosen:
>
> Acked-by: Tudor Ambarus <tudor.ambarus@linaro.org>

Thanks,
Miquèl

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