[PATCH 1/2] net: sh_eth: Fix receive packet "exceeded" condition in sh_eth_rx()

[PATCH 1/2] net: sh_eth: Fix receive packet "exceeded" condition in sh_eth_rx()

[Yoshihiro Shimoda]

This patch fixes the packet "exceeded" condition in sh_eth_rx() when
RACT in an RX descriptor is not set and the "quota" is 0.
Otherwise, kernel panic happens because the "&n->poll_list" is deleted
twice in sh_eth_poll() which calls napi_complete() and net_rx_action().

Signed-off-by: Kouei Abe <kouei.abe.cp@renesas.com>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 drivers/net/ethernet/renesas/sh_eth.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index 08ed9a3..ad0b5bd 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1399,7 +1399,6 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota)
 	int entry = mdp->cur_rx % mdp->num_rx_ring;
 	int boguscnt = (mdp->dirty_rx + mdp->num_rx_ring) - mdp->cur_rx;
 	struct sk_buff *skb;
-	int exceeded = 0;
 	u16 pkt_len = 0;
 	u32 desc_status;

@@ -1411,10 +1410,9 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota)
 		if (--boguscnt < 0)
 			break;

-		if (*quota <= 0) {
-			exceeded = 1;
+		if (*quota <= 0)
 			break;
-		}
+
 		(*quota)--;

 		if (!(desc_status & RDFEND))
@@ -1508,7 +1506,7 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota)
 		sh_eth_write(ndev, EDRRR_R, EDRRR);
 	}

-	return exceeded;
+	return (*quota <= 0);
 }

 static void sh_eth_rcv_snd_disable(struct net_device *ndev)
-- 
1.7.9.5

Re: [PATCH 1/2] net: sh_eth: Fix receive packet "exceeded" condition in sh_eth_rx()

[Sergei Shtylyov]

Hello.

On 09-06-2014 14:39, Yoshihiro Shimoda wrote:

> This patch fixes the packet "exceeded" condition in sh_eth_rx() when
> RACT in an RX descriptor is not set and the "quota" is 0.
> Otherwise, kernel panic happens because the "&n->poll_list" is deleted
> twice in sh_eth_poll() which calls napi_complete() and net_rx_action().

> Signed-off-by: Kouei Abe <kouei.abe.cp@renesas.com>
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> ---
>   drivers/net/ethernet/renesas/sh_eth.c |    8 +++-----
>   1 file changed, 3 insertions(+), 5 deletions(-)

> diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
> index 08ed9a3..ad0b5bd 100644
> --- a/drivers/net/ethernet/renesas/sh_eth.c
> +++ b/drivers/net/ethernet/renesas/sh_eth.c
[...]
> @@ -1508,7 +1506,7 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota)
>   		sh_eth_write(ndev, EDRRR_R, EDRRR);
>   	}
>
> -	return exceeded;
> +	return (*quota <= 0);

    Parens not needed here.

WBR, Sergei

Re: [PATCH 1/2] net: sh_eth: Fix receive packet "exceeded" condition in sh_eth_rx()

[Yoshihiro Shimoda]

Hello.

(2014/06/09 19:58), Sergei Shtylyov wrote:
> Hello.
> 
> On 09-06-2014 14:39, Yoshihiro Shimoda wrote:
> 
>> This patch fixes the packet "exceeded" condition in sh_eth_rx() when
>> RACT in an RX descriptor is not set and the "quota" is 0.
>> Otherwise, kernel panic happens because the "&n->poll_list" is deleted
>> twice in sh_eth_poll() which calls napi_complete() and net_rx_action().
> 
>> Signed-off-by: Kouei Abe <kouei.abe.cp@renesas.com>
>> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
>> ---
>>   drivers/net/ethernet/renesas/sh_eth.c |    8 +++-----
>>   1 file changed, 3 insertions(+), 5 deletions(-)
> 
>> diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
>> index 08ed9a3..ad0b5bd 100644
>> --- a/drivers/net/ethernet/renesas/sh_eth.c
>> +++ b/drivers/net/ethernet/renesas/sh_eth.c
> [...]
>> @@ -1508,7 +1506,7 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota)
>>           sh_eth_write(ndev, EDRRR_R, EDRRR);
>>       }
>>
>> -    return exceeded;
>> +    return (*quota <= 0);
> 
>    Parens not needed here.

Thank you for the point. I will remove the parens.

Best regards,
Yoshihiro Shimoda

> WBR, Sergei
>