[PATCH] mtd: rawnand: marvell: fix the IRQ handler complete() condition

[PATCH] mtd: rawnand: marvell: fix the IRQ handler complete() condition

[Miquel Raynal]

With the current implementation, the complete() in the IRQ handler is
supposed to be called only if the register status has one or the other
RDY bit set. Other events might trigger an interrupt as well if
enabled, but should not end-up with a complete() call.

For this purpose, the code was checking if the other bits were set, in
this case complete() was not called. This is wrong as two events might
happen in a very tight time-frame and if the NDSR status read reports
two bits set (eg. RDY(0) and RDDREQ) at the same time, complete() was
not called.

This logic would lead to timeouts in marvell_nfc_wait_op() and has
been observed on PXA boards (NFCv1) in the Hamming write path.

Fixes: 02f26ecf8c77 ("mtd: nand: add reworked Marvell NAND controller driver")
Cc: stable@vger.kernel.org
Reported-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Daniel Mack <daniel@zonque.org>
---
 drivers/mtd/nand/raw/marvell_nand.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/raw/marvell_nand.c b/drivers/mtd/nand/raw/marvell_nand.c
index bc2ef5209783..c7573ccdbacd 100644
--- a/drivers/mtd/nand/raw/marvell_nand.c
+++ b/drivers/mtd/nand/raw/marvell_nand.c
@@ -686,7 +686,7 @@ static irqreturn_t marvell_nfc_isr(int irq, void *dev_id)
 
 	marvell_nfc_disable_int(nfc, st & NDCR_ALL_INT);
 
-	if (!(st & (NDSR_RDDREQ | NDSR_WRDREQ | NDSR_WRCMDREQ)))
+	if (st & (NDSR_RDY(0) | NDSR_RDY(1)))
 		complete(&nfc->complete);
 
 	return IRQ_HANDLED;
-- 
2.17.1

Re: [PATCH] mtd: rawnand: marvell: fix the IRQ handler complete() condition

[Boris Brezillon]

On Wed,  3 Oct 2018 11:05:04 +0200
Miquel Raynal <miquel.raynal@bootlin.com> wrote:

> With the current implementation, the complete() in the IRQ handler is
> supposed to be called only if the register status has one or the other
> RDY bit set. Other events might trigger an interrupt as well if
> enabled, but should not end-up with a complete() call.
> 
> For this purpose, the code was checking if the other bits were set, in
> this case complete() was not called. This is wrong as two events might
> happen in a very tight time-frame and if the NDSR status read reports
> two bits set (eg. RDY(0) and RDDREQ) at the same time, complete() was
> not called.
> 
> This logic would lead to timeouts in marvell_nfc_wait_op() and has
> been observed on PXA boards (NFCv1) in the Hamming write path.
> 
> Fixes: 02f26ecf8c77 ("mtd: nand: add reworked Marvell NAND controller driver")
> Cc: stable@vger.kernel.org
> Reported-by: Daniel Mack <daniel@zonque.org>
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> Tested-by: Daniel Mack <daniel@zonque.org>

Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>

> ---
>  drivers/mtd/nand/raw/marvell_nand.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/nand/raw/marvell_nand.c b/drivers/mtd/nand/raw/marvell_nand.c
> index bc2ef5209783..c7573ccdbacd 100644
> --- a/drivers/mtd/nand/raw/marvell_nand.c
> +++ b/drivers/mtd/nand/raw/marvell_nand.c
> @@ -686,7 +686,7 @@ static irqreturn_t marvell_nfc_isr(int irq, void *dev_id)
>  
>  	marvell_nfc_disable_int(nfc, st & NDCR_ALL_INT);
>  
> -	if (!(st & (NDSR_RDDREQ | NDSR_WRDREQ | NDSR_WRCMDREQ)))
> +	if (st & (NDSR_RDY(0) | NDSR_RDY(1)))
>  		complete(&nfc->complete);
>  
>  	return IRQ_HANDLED;

Re: [PATCH] mtd: rawnand: marvell: fix the IRQ handler complete() condition

[Miquel Raynal]

Hello

Miquel Raynal <miquel.raynal@bootlin.com> wrote on Wed,  3 Oct 2018
11:05:04 +0200:

> With the current implementation, the complete() in the IRQ handler is
> supposed to be called only if the register status has one or the other
> RDY bit set. Other events might trigger an interrupt as well if
> enabled, but should not end-up with a complete() call.
> 
> For this purpose, the code was checking if the other bits were set, in
> this case complete() was not called. This is wrong as two events might
> happen in a very tight time-frame and if the NDSR status read reports
> two bits set (eg. RDY(0) and RDDREQ) at the same time, complete() was
> not called.
> 
> This logic would lead to timeouts in marvell_nfc_wait_op() and has
> been observed on PXA boards (NFCv1) in the Hamming write path.
> 
> Fixes: 02f26ecf8c77 ("mtd: nand: add reworked Marvell NAND controller driver")
> Cc: stable@vger.kernel.org
> Reported-by: Daniel Mack <daniel@zonque.org>
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> Tested-by: Daniel Mack <daniel@zonque.org>
> ---
>  drivers/mtd/nand/raw/marvell_nand.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/nand/raw/marvell_nand.c b/drivers/mtd/nand/raw/marvell_nand.c
> index bc2ef5209783..c7573ccdbacd 100644
> --- a/drivers/mtd/nand/raw/marvell_nand.c
> +++ b/drivers/mtd/nand/raw/marvell_nand.c
> @@ -686,7 +686,7 @@ static irqreturn_t marvell_nfc_isr(int irq, void *dev_id)
>  
>  	marvell_nfc_disable_int(nfc, st & NDCR_ALL_INT);
>  
> -	if (!(st & (NDSR_RDDREQ | NDSR_WRDREQ | NDSR_WRCMDREQ)))
> +	if (st & (NDSR_RDY(0) | NDSR_RDY(1)))
>  		complete(&nfc->complete);
>  
>  	return IRQ_HANDLED;

Applied to nand/next.