Mike,
Please explain why the patch below is any better/worse than the
patch here:
http://marc.theaimsgroup.com/?l=linux-netdev&m=112997172112090&w=2
Thanks!
John
On Sat, Nov 05, 2005 at 01:47:00PM -0500, Mike Kershaw wrote:
> Josh Wright and I encountered this doing rawtx experiements some time
> ago. I bounced it to the prism54 guys but it must have gotten lost in
> the shuffle and we just noticed that it's still in the latest kernel so
> here we go again.
>
> PROBLEM:
> Prism54 assumes frames must be at least ETH_ZLEN in size, and grows the
> skb to that size if they are not. However, it doesn't clear the grown
> skb so anything left in kernel buffers gets throw into the packet and
> transmitted onto the air.
>
> SOLUTION:
> Don't grow the frame size. 802.11 doesn't have a minimum frame size
> constraint. This was addressed on the Orinoco drivers recently in a
> similar situation. After talking to the Prism54 team there appears to
> be no constraint in the prism54 firmware that would prevent sending
> short frames like this.
>
> Patch attached.
>
> Signed off by: Mike Kershaw <[EMAIL PROTECTED]>
>
>
> --
> Mike Kershaw/Dragorn <[EMAIL PROTECTED]>
> GPG Fingerprint: 3546 89DF 3C9D ED80 3381 A661 D7B2 8822 738B BDB1
>
> Bus Error at 008BE426 while reading byte from DEADBEEF in User data space
>
> diff --git a/drivers/net/wireless/prism54/islpci_eth.c
> b/drivers/net/wireless/prism54/islpci_eth.c
> index 5952e99..a2558c2 100644
> --- a/drivers/net/wireless/prism54/islpci_eth.c
> +++ b/drivers/net/wireless/prism54/islpci_eth.c
> @@ -99,7 +99,9 @@ islpci_eth_transmit(struct sk_buff *skb,
>
> /* determine the amount of fragments needed to store the frame */
>
> - frame_size = skb->len < ETH_ZLEN ? ETH_ZLEN : skb->len;
> + /* Previously this was calculated by enforcing that a frame had to be
> as
> + * large as ETH_ZLEN, however this should not be necessary on 802.11
> frames */
> + frame_size = skb->len;
> if (init_wds)
> frame_size += 6;
>
--
John W. Linville
[EMAIL PROTECTED]
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