[PATCH] net: airoha: Fix always-true condition in PPE1 queue reservation loop

[PATCH] net: airoha: Fix always-true condition in PPE1 queue reservation loop

[Wayen.Yan]

In airoha_fe_pse_ports_init(), the inner condition for PPE1 queue
reservation is identical to the for-loop bound, making it always true
and the else branch dead code:

  for (q = 0; q < pse_port_num_queues[FE_PSE_PORT_PPE1]; q++) {
      if (q < pse_port_num_queues[FE_PSE_PORT_PPE1])  /* always true */
          set RSV_PAGES;
      else
          set 0;  /* unreachable */
  }

The intended behavior is to reserve pages only for the first half of
the queues, matching the PPE2 implementation on line 334 which
correctly uses the /2 divisor. Fix the PPE1 condition accordingly.

Fixes: 23020f049327 ("net: airoha: Introduce ethernet support for EN7581 SoC")
Signed-off-by: Wayen.Yan <win847@gmail.com>
---
 drivers/net/ethernet/airoha/airoha_eth.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
index 31cdb11..999f517 100644
--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c
@@ -311,7 +311,7 @@ static void airoha_fe_pse_ports_init(struct airoha_eth *eth)
 					 PSE_QUEUE_RSV_PAGES);
 	/* PPE1 */
 	for (q = 0; q < pse_port_num_queues[FE_PSE_PORT_PPE1]; q++) {
-		if (q < pse_port_num_queues[FE_PSE_PORT_PPE1])
+		if (q < pse_port_num_queues[FE_PSE_PORT_PPE1] / 2)
 			airoha_fe_set_pse_oq_rsv(eth, FE_PSE_PORT_PPE1, q,
 						 PSE_QUEUE_RSV_PAGES);
 		else
-- 
2.51.0

Re: [PATCH] net: airoha: Fix always-true condition in PPE1 queue reservation loop

[Lorenzo Bianconi]

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> In airoha_fe_pse_ports_init(), the inner condition for PPE1 queue
> reservation is identical to the for-loop bound, making it always true
> and the else branch dead code:
> 
>   for (q = 0; q < pse_port_num_queues[FE_PSE_PORT_PPE1]; q++) {
>       if (q < pse_port_num_queues[FE_PSE_PORT_PPE1])  /* always true */
>           set RSV_PAGES;
>       else
>           set 0;  /* unreachable */
>   }
> 
> The intended behavior is to reserve pages only for the first half of
> the queues, matching the PPE2 implementation on line 334 which
> correctly uses the /2 divisor. Fix the PPE1 condition accordingly.
> 
> Fixes: 23020f049327 ("net: airoha: Introduce ethernet support for EN7581 SoC")
> Signed-off-by: Wayen.Yan <win847@gmail.com>

Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>

> ---
>  drivers/net/ethernet/airoha/airoha_eth.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
> index 31cdb11..999f517 100644
> --- a/drivers/net/ethernet/airoha/airoha_eth.c
> +++ b/drivers/net/ethernet/airoha/airoha_eth.c
> @@ -311,7 +311,7 @@ static void airoha_fe_pse_ports_init(struct airoha_eth *eth)
>  					 PSE_QUEUE_RSV_PAGES);
>  	/* PPE1 */
>  	for (q = 0; q < pse_port_num_queues[FE_PSE_PORT_PPE1]; q++) {
> -		if (q < pse_port_num_queues[FE_PSE_PORT_PPE1])
> +		if (q < pse_port_num_queues[FE_PSE_PORT_PPE1] / 2)
>  			airoha_fe_set_pse_oq_rsv(eth, FE_PSE_PORT_PPE1, q,
>  						 PSE_QUEUE_RSV_PAGES);
>  		else
> -- 
> 2.51.0
> 
> 

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