[PATCH] ucc_geth: Add 8 bytes to max TX frame for VLANs

Li Yang LeoLi at freescale.com
Fri Mar 21 23:20:34 EST 2008


> -----Original Message-----
> From: netdev-owner at vger.kernel.org 
> [mailto:netdev-owner at vger.kernel.org] On Behalf Of Joakim Tjernlund
> Sent: Tuesday, March 18, 2008 11:11 PM
> To: Netdev; Li Yang
> Cc: Joakim Tjernlund
> Subject: [PATCH] ucc_geth: Add 8 bytes to max TX frame for VLANs
> 
> Creating a VLAN interface on top of ucc_geth adds 4 bytes to 
> the frame and the HW controller is not prepared to TX a frame 
> bigger than 1518 bytes which is 4 bytes too small for a full 
> VLAN frame. Also add 4 extra bytes for future expansion.

IMO, VLAN and Jumbo packet support is not general case of Ethernet.
Could you make this change optional?  Thanks.

- Leo

> 
> Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund at transmode.se>
> ---
>  drivers/net/ucc_geth.c |    6 +++---
>  1 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c 
> index 348892b..038ec75 100644
> --- a/drivers/net/ucc_geth.c
> +++ b/drivers/net/ucc_geth.c
> @@ -114,10 +114,10 @@ static struct ucc_geth_info 
> ugeth_primary_info = {
>  	.maxGroupAddrInHash = 4,
>  	.maxIndAddrInHash = 4,
>  	.prel = 7,
> -	.maxFrameLength = 1518,
> +	.maxFrameLength = 1518+8, /* Add 4 bytes for VLAN tags 
> and 4 extra 
> +bytes */
>  	.minFrameLength = 64,
> -	.maxD1Length = 1520,
> -	.maxD2Length = 1520,
> +	.maxD1Length = 1520+8,
> +	.maxD2Length = 1520+8,
>  	.vlantype = 0x8100,
>  	.ecamptr = ((uint32_t) NULL),
>  	.eventRegMask = UCCE_OTHER,
> --
> 1.5.4.3
> 
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