* re: mlx4_en: Using blue flame support
@ 2013-12-17 11:57 Dan Carpenter
2013-12-17 12:55 ` Amir Vadai
0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2013-12-17 11:57 UTC (permalink / raw)
To: kernel-janitors
Hello Yevgeny Petrilin,
The patch 87a5c3896f9c: "mlx4_en: Using blue flame support" from
Mar 22, 2011, leads to the following static checker warning:
drivers/net/ethernet/mellanox/mlx4/en_tx.c:839 mlx4_en_xmit()
warn: potential memory corrupting cast 4 vs 2 bytes
drivers/net/ethernet/mellanox/mlx4/en_tx.c
771 tx_desc->ctrl.ins_vlan = MLX4_WQE_CTRL_INS_VLAN *
772 !!vlan_tx_tag_present(skb);
773 tx_desc->ctrl.fence_size = (real_size / 16) & 0x3f;
We set ->ctrl.ins_vlan and ->ctrl.fence_size here.
774 tx_desc->ctrl.srcrb_flags = priv->ctrl_flags;
775 if (likely(skb->ip_summed = CHECKSUM_PARTIAL)) {
776 tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM |
777 MLX4_WQE_CTRL_TCP_UDP_CSUM);
778 ring->tx_csum++;
779 }
[ snip ]
838 if (ring->bf_enabled && desc_size <= MAX_BF && !bounce && !vlan_tx_tag_present(skb)) {
839 *(__be32 *) (&tx_desc->ctrl.vlan_tag) |= cpu_to_be32(ring->doorbell_qpn);
And then sometimes we overwrite them here. It's not clear if this is
deliberate or accidental. Maybe add a comment?
840 op_own |= htonl((bf_index & 0xffff) << 8);
841 /* Ensure new descirptor hits memory
842 * before setting ownership of this descriptor to HW */
843 wmb();
844 tx_desc->ctrl.owner_opcode = op_own;
845
846 wmb();
regards,
dan carpenter
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: mlx4_en: Using blue flame support
2013-12-17 11:57 mlx4_en: Using blue flame support Dan Carpenter
@ 2013-12-17 12:55 ` Amir Vadai
0 siblings, 0 replies; 2+ messages in thread
From: Amir Vadai @ 2013-12-17 12:55 UTC (permalink / raw)
To: kernel-janitors
On 17/12/2013 13:57, Dan Carpenter wrote:
> 838 if (ring->bf_enabled && desc_size <= MAX_BF && !bounce && !vlan_tx_tag_present(skb)) {
> 839 *(__be32 *) (&tx_desc->ctrl.vlan_tag) |= cpu_to_be32(ring->doorbell_qpn);
>
> And then sometimes we overwrite them here. It's not clear if this is
> deliberate or accidental. Maybe add a comment?
Yes, this is deliberate.
I will send a patch to make it clearer.
Amir
^ permalink raw reply [flat|nested] 2+ messages in thread
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