Make sure to drop the reference taken to the DMA master OF node also on
late route allocation failures.

Fixes: 134d9c52fca2 ("dmaengine: dw: dmamux: Introduce RZN1 DMA router support")
Cc: stable@vger.kernel.org	# 5.19
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/dma/dw/rzn1-dmamux.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/dw/rzn1-dmamux.c b/drivers/dma/dw/rzn1-dmamux.c
index deadf135681b..cbec277af4dd 100644
--- a/drivers/dma/dw/rzn1-dmamux.c
+++ b/drivers/dma/dw/rzn1-dmamux.c
@@ -90,7 +90,7 @@ static void *rzn1_dmamux_route_allocate(struct of_phandle_args *dma_spec,
 
 	if (test_and_set_bit(map->req_idx, dmamux->used_chans)) {
 		ret = -EBUSY;
-		goto free_map;
+		goto put_dma_spec_np;
 	}
 
 	mask = BIT(map->req_idx);
@@ -103,6 +103,8 @@ static void *rzn1_dmamux_route_allocate(struct of_phandle_args *dma_spec,
 
 clear_bitmap:
 	clear_bit(map->req_idx, dmamux->used_chans);
+put_dma_spec_np:
+	of_node_put(dma_spec->np);
 free_map:
 	kfree(map);
 put_device:
-- 
2.51.0

On Mon, Nov 17, 2025 at 05:12:47PM +0100, Johan Hovold wrote:
> Make sure to drop the reference taken to the DMA master OF node also on
> late route allocation failures.

...

> +put_dma_spec_np:
> +	of_node_put(dma_spec->np);

Can we use __free() instead?

(Just in case you are going to question the appearance of cleanup.h and the
 respective class in of.h, it's available in the closest stable, i.e.
 v6.1.108 onwards).

-- 
With Best Regards,
Andy Shevchenko

Hi Andy,

On 17/11/2025 at 18:05:47 +01, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> On Mon, Nov 17, 2025 at 05:12:47PM +0100, Johan Hovold wrote:
>> Make sure to drop the reference taken to the DMA master OF node also on
>> late route allocation failures.
>
> ...
>
>> +put_dma_spec_np:
>> +	of_node_put(dma_spec->np);
>
> Can we use __free() instead?

I probably haven't followed closely enough, but I don't understand how
__free() is best than of_node_put() in front of of_parse_phandle()?
Especially since the doc clearly states

           "Return: The device_node pointer with refcount incremented.
           Use of_node_put() on it when done."

> (Just in case you are going to question the appearance of cleanup.h and the
>  respective class in of.h, it's available in the closest stable, i.e.
>  v6.1.108 onwards).

I don't believe including a recent header is a good practice for stable
inclusion anyway. I would recommend to let the commit as it is and in a
follow-up patch, maybe, we can move to a newer API if we want. This way
history between stable and mailine versions is easier to compare.

Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>

Thanks,
Miquèl

On Mon, Nov 17, 2025 at 06:05:47PM +0100, Andy Shevchenko wrote:
> On Mon, Nov 17, 2025 at 05:12:47PM +0100, Johan Hovold wrote:
> > Make sure to drop the reference taken to the DMA master OF node also on
> > late route allocation failures.
> 
> ...
> 
> > +put_dma_spec_np:
> > +	of_node_put(dma_spec->np);
> 
> Can we use __free() instead?

I'm no fan of __free() but here it's a particularly bad fit, so no.

Johan