[PATCH v2 1/1] net: fs_enet: Fix NETIF_F_SG feature for Freescale MPC5121

[David Miller]

From: Alexander Popov <alex.popov at linux.com>
Date: Sun, 21 Jun 2015 01:32:46 +0300

> Commit 4fc9b87bae25 ("net: fs_enet: Implement NETIF_F_SG feature")
> brings a trouble to Freescale MPC512x: a kernel oops happens
> during sending non-linear sk_buff with .data not aligned by 4.
> 
> Log quotation:
 ...
> The reason:
> 
> MPC5121 FEC requires 4-byte alignment for TX data buffer and calls
> tx_skb_align_workaround() for copying sk_buff with not aligned .data to a new
> sk_buff with aligned one. But tx_skb_align_workaround() uses
> skb_copy_from_linear_data() which doesn't work for non-linear sk_buff:
> a new sk_buff has non-zero nr_frags and zero .data_len.
> 
> So improve the condition of calling tx_skb_align_workaround() and use
> skb_linearize() in it.
> 
> Signed-off-by: Alexander Popov <alex.popov at linux.com>

Applied, thanks.