qca8k_port_bridge_join() set QCA8K_PORT_LOOKUP_CTRL() for i == port twice,
once in the loop handling all other port's masks, and finally at the end
with the accumulated port_mask.

The first time it would incorrectly set the port's own bit in the mask,
only to correct the mistake a moment later. qca8k_port_bridge_leave() had
the same issue, but here the regmap_clear_bits() was a no-op rather than
setting an unintended value.

Remove the duplicate assignment by skipping the whole loop iteration for
i == port. The unintended bit setting doesn't seem to have any negative
effects (even when not reverted right away), so the change is submitted
as a simple cleanup rather than a fix.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
---
 drivers/net/dsa/qca/qca8k-common.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/qca/qca8k-common.c b/drivers/net/dsa/qca/qca8k-common.c
index 7f80035c5441..b33df84070d3 100644
--- a/drivers/net/dsa/qca/qca8k-common.c
+++ b/drivers/net/dsa/qca/qca8k-common.c
@@ -653,6 +653,8 @@ int qca8k_port_bridge_join(struct dsa_switch *ds, int port,
 	port_mask = BIT(cpu_port);
 
 	for (i = 0; i < QCA8K_NUM_PORTS; i++) {
+		if (i == port)
+			continue;
 		if (dsa_is_cpu_port(ds, i))
 			continue;
 		if (!dsa_port_offloads_bridge(dsa_to_port(ds, i), &bridge))
@@ -665,8 +667,7 @@ int qca8k_port_bridge_join(struct dsa_switch *ds, int port,
 				      BIT(port));
 		if (ret)
 			return ret;
-		if (i != port)
-			port_mask |= BIT(i);
+		port_mask |= BIT(i);
 	}
 
 	/* Add all other ports to this ports portvlan mask */
@@ -685,6 +686,8 @@ void qca8k_port_bridge_leave(struct dsa_switch *ds, int port,
 	cpu_port = dsa_to_port(ds, port)->cpu_dp->index;
 
 	for (i = 0; i < QCA8K_NUM_PORTS; i++) {
+		if (i == port)
+			continue;
 		if (dsa_is_cpu_port(ds, i))
 			continue;
 		if (!dsa_port_offloads_bridge(dsa_to_port(ds, i), &bridge))
-- 
2.45.2

On 20.06.2024 19:25, Matthias Schiffer wrote:
> qca8k_port_bridge_join() set QCA8K_PORT_LOOKUP_CTRL() for i == port twice,
> once in the loop handling all other port's masks, and finally at the end
> with the accumulated port_mask.
> 
> The first time it would incorrectly set the port's own bit in the mask,
> only to correct the mistake a moment later. qca8k_port_bridge_leave() had
> the same issue, but here the regmap_clear_bits() was a no-op rather than
> setting an unintended value.
> 
> Remove the duplicate assignment by skipping the whole loop iteration for
> i == port. The unintended bit setting doesn't seem to have any negative
> effects (even when not reverted right away), so the change is submitted
> as a simple cleanup rather than a fix.
> 
> Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
> ---

Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>

>  drivers/net/dsa/qca/qca8k-common.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/dsa/qca/qca8k-common.c b/drivers/net/dsa/qca/qca8k-common.c
> index 7f80035c5441..b33df84070d3 100644
> --- a/drivers/net/dsa/qca/qca8k-common.c
> +++ b/drivers/net/dsa/qca/qca8k-common.c
> @@ -653,6 +653,8 @@ int qca8k_port_bridge_join(struct dsa_switch *ds, int port,
>  	port_mask = BIT(cpu_port);
>  
>  	for (i = 0; i < QCA8K_NUM_PORTS; i++) {
> +		if (i == port)
> +			continue;
>  		if (dsa_is_cpu_port(ds, i))
>  			continue;
>  		if (!dsa_port_offloads_bridge(dsa_to_port(ds, i), &bridge))
> @@ -665,8 +667,7 @@ int qca8k_port_bridge_join(struct dsa_switch *ds, int port,
>  				      BIT(port));
>  		if (ret)
>  			return ret;
> -		if (i != port)
> -			port_mask |= BIT(i);
> +		port_mask |= BIT(i);
>  	}
>  
>  	/* Add all other ports to this ports portvlan mask */
> @@ -685,6 +686,8 @@ void qca8k_port_bridge_leave(struct dsa_switch *ds, int port,
>  	cpu_port = dsa_to_port(ds, port)->cpu_dp->index;
>  
>  	for (i = 0; i < QCA8K_NUM_PORTS; i++) {
> +		if (i == port)
> +			continue;
>  		if (dsa_is_cpu_port(ds, i))
>  			continue;
>  		if (!dsa_port_offloads_bridge(dsa_to_port(ds, i), &bridge))