[PATCH v2] of_firmware: fix lookup of fpga manager

[PATCH v2] of_firmware: fix lookup of fpga manager

[Michael Tretter]

The of_parse_phandle() looks for the phandle in the root device tree,
but as np is resolved for the target device tree, the phandle refers to
the target device tree and may return a wrong node in the root tree.

Therefore, we must ensure that we look for the manager-node in the
target device tree, which is the root node of np, and look for the
manager with that name.

firmwaremgr_find_by_node already uses the name for the lookup.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
---
Changelog:

v1 -> v2:

- Use of_parse_phandle_from instead of open coding the phandle lookup
---
 drivers/of/of_firmware.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/of/of_firmware.c b/drivers/of/of_firmware.c
index 80feb3b90dba..c1b69aac045c 100644
--- a/drivers/of/of_firmware.c
+++ b/drivers/of/of_firmware.c
@@ -11,7 +11,8 @@ static struct firmware_mgr *of_node_get_mgr(struct device_node *np)
 	struct device_node *mgr_node;
 
 	do {
-		mgr_node = of_parse_phandle(np, "fpga-mgr", 0);
+		mgr_node = of_parse_phandle_from(np, of_find_root_node(np),
+						 "fpga-mgr", 0);
 		if (mgr_node)
 			return firmwaremgr_find_by_node(mgr_node);
 	} while ((np = of_get_parent(np)) != NULL);
-- 
2.39.2

Re: [PATCH v2] of_firmware: fix lookup of fpga manager

[Sascha Hauer]

On Wed, Aug 09, 2023 at 12:05:59PM +0200, Michael Tretter wrote:
> The of_parse_phandle() looks for the phandle in the root device tree,
> but as np is resolved for the target device tree, the phandle refers to
> the target device tree and may return a wrong node in the root tree.
> 
> Therefore, we must ensure that we look for the manager-node in the
> target device tree, which is the root node of np, and look for the
> manager with that name.
> 
> firmwaremgr_find_by_node already uses the name for the lookup.
> 
> Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
> ---
> Changelog:
> 
> v1 -> v2:
> 
> - Use of_parse_phandle_from instead of open coding the phandle lookup
> ---
>  drivers/of/of_firmware.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Applied, thanks

Sascha

> 
> diff --git a/drivers/of/of_firmware.c b/drivers/of/of_firmware.c
> index 80feb3b90dba..c1b69aac045c 100644
> --- a/drivers/of/of_firmware.c
> +++ b/drivers/of/of_firmware.c
> @@ -11,7 +11,8 @@ static struct firmware_mgr *of_node_get_mgr(struct device_node *np)
>  	struct device_node *mgr_node;
>  
>  	do {
> -		mgr_node = of_parse_phandle(np, "fpga-mgr", 0);
> +		mgr_node = of_parse_phandle_from(np, of_find_root_node(np),
> +						 "fpga-mgr", 0);
>  		if (mgr_node)
>  			return firmwaremgr_find_by_node(mgr_node);
>  	} while ((np = of_get_parent(np)) != NULL);
> -- 
> 2.39.2
> 
> 
> 

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