[PATCH] net: sh_eth: fix skb_over_panic happen

[PATCH] net: sh_eth: fix skb_over_panic happen

[Shimoda, Yoshihiro]

When this GETHER controller received a large frame (about 1800 bytes
or more), skb_over_panic() happened. This is because the previous
driver set the RFLR to 0x1000 (4096 bytes) and the skb allocate size
is smaller than 4096 bytes. So, the controller accepted such a frame.

The controller can discard a large frame by the RFLR setting.
So, the patch modifies the value of RFLR to mtu + ETH_HLEN +
ETH_FCS_LEN.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 drivers/net/ethernet/renesas/sh_eth.c |    2 +-
 drivers/net/ethernet/renesas/sh_eth.h |    3 ---
 2 files changed, 1 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index 813d41c..9e899b0 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -817,7 +817,7 @@ static int sh_eth_dev_init(struct net_device *ndev)
 		sh_eth_write(ndev, 0, TRIMD);

 	/* Recv frame limit set register */
-	sh_eth_write(ndev, RFLR_VALUE, RFLR);
+	sh_eth_write(ndev, ndev->mtu + ETH_HLEN + ETH_FCS_LEN, RFLR);

 	sh_eth_write(ndev, sh_eth_read(ndev, EESR), EESR);
 	sh_eth_write(ndev, mdp->cd->eesipr_value, EESIPR);
diff --git a/drivers/net/ethernet/renesas/sh_eth.h b/drivers/net/ethernet/renesas/sh_eth.h
index 47877b1..cdbd844 100644
--- a/drivers/net/ethernet/renesas/sh_eth.h
+++ b/drivers/net/ethernet/renesas/sh_eth.h
@@ -575,9 +575,6 @@ enum RPADIR_BIT {
 	RPADIR_PADR = 0x0003f,
 };

-/* RFLR */
-#define RFLR_VALUE 0x1000
-
 /* FDR */
 #define DEFAULT_FDR_INIT	0x00000707

-- 
1.7.1

Re: [PATCH] net: sh_eth: fix skb_over_panic happen

[Eric Dumazet]

Le mardi 07 février 2012 à 15:54 +0900, Shimoda, Yoshihiro a écrit :
> When this GETHER controller received a large frame (about 1800 bytes
> or more), skb_over_panic() happened. This is because the previous
> driver set the RFLR to 0x1000 (4096 bytes) and the skb allocate size
> is smaller than 4096 bytes. So, the controller accepted such a frame.
> 
> The controller can discard a large frame by the RFLR setting.
> So, the patch modifies the value of RFLR to mtu + ETH_HLEN +
> ETH_FCS_LEN.
> 
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> ---
>  drivers/net/ethernet/renesas/sh_eth.c |    2 +-
>  drivers/net/ethernet/renesas/sh_eth.h |    3 ---
>  2 files changed, 1 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
> index 813d41c..9e899b0 100644
> --- a/drivers/net/ethernet/renesas/sh_eth.c
> +++ b/drivers/net/ethernet/renesas/sh_eth.c
> @@ -817,7 +817,7 @@ static int sh_eth_dev_init(struct net_device *ndev)
>  		sh_eth_write(ndev, 0, TRIMD);
> 
>  	/* Recv frame limit set register */
> -	sh_eth_write(ndev, RFLR_VALUE, RFLR);
> +	sh_eth_write(ndev, ndev->mtu + ETH_HLEN + ETH_FCS_LEN, RFLR);
> 

No VLAN_HDR ?

Re: [PATCH] net: sh_eth: fix skb_over_panic happen

[Shimoda, Yoshihiro]

Hi Eric,

2012/02/07 16:55, Eric Dumazet wrote:
> Le mardi 07 février 2012 à 15:54 +0900, Shimoda, Yoshihiro a écrit :
[ snip ]
>> diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
>> index 813d41c..9e899b0 100644
>> --- a/drivers/net/ethernet/renesas/sh_eth.c
>> +++ b/drivers/net/ethernet/renesas/sh_eth.c
>> @@ -817,7 +817,7 @@ static int sh_eth_dev_init(struct net_device *ndev)
>>  		sh_eth_write(ndev, 0, TRIMD);
>>
>>  	/* Recv frame limit set register */
>> -	sh_eth_write(ndev, RFLR_VALUE, RFLR);
>> +	sh_eth_write(ndev, ndev->mtu + ETH_HLEN + ETH_FCS_LEN, RFLR);
>>
> 
> No VLAN_HDR ?
> 

Thank you for your point.
I forgot care of VLAN. I will add "+ VLAN_HLEN" and submit a patch.

Best regards,
Yoshihiro Shimoda