[net-intel-i40e] question about assignment overwrite

Gustavo A. R. Silva
2017-05-17T20:49:10Z

Hello everybody,

While looking into Coverity ID 1408956 I ran into the following piece
of code at drivers/net/ethernet/intel/i40e/i40e_main.c:8807:

8807 if (pf->hw.mac.type == I40E_MAC_X722) {
8808 pf->flags |= I40E_FLAG_RSS_AQ_CAPABLE
8809 | I40E_FLAG_128_QP_RSS_CAPABLE
8810 | I40E_FLAG_HW_ATR_EVICT_CAPABLE
8811 | I40E_FLAG_OUTER_UDP_CSUM_CAPABLE
8812 | I40E_FLAG_WB_ON_ITR_CAPABLE
8813 | I40E_FLAG_MULTIPLE_TCP_UDP_RSS_PCTYPE
8814 | I40E_FLAG_NO_PCI_LINK_CHECK
8815 | I40E_FLAG_USE_SET_LLDP_MIB
8816 | I40E_FLAG_GENEVE_OFFLOAD_CAPABLE
8817 | I40E_FLAG_PTP_L4_CAPABLE
8818 | I40E_FLAG_WOL_MC_MAGIC_PKT_WAKE;
8819 } else if ((pf->hw.aq.api_maj_ver > 1) ||
8820 ((pf->hw.aq.api_maj_ver == 1) &&
8821 (pf->hw.aq.api_min_ver > 4))) {
8822 /* Supported in FW API version higher than 1.4 */
8823 pf->flags |= I40E_FLAG_GENEVE_OFFLOAD_CAPABLE;
8824 pf->flags = I40E_FLAG_HW_ATR_EVICT_CAPABLE;
8825 } else {
8826 pf->flags = I40E_FLAG_HW_ATR_EVICT_CAPABLE;
8827 }

The issue here is that the assignment at line 8823 is overwritten by
the code at line 8824.

I'm suspicious that line 8824 should be remove and a patch like the
following can be applied:

index d5c9c9e..48ffa73 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -8821,7 +8821,6 @@ static int i40e_sw_init(struct i40e_pf *pf)
(pf->hw.aq.api_min_ver > 4))) {
/* Supported in FW API version higher than 1.4 */
pf->flags |= I40E_FLAG_GENEVE_OFFLOAD_CAPABLE;
- pf->flags = I40E_FLAG_HW_ATR_EVICT_CAPABLE;
} else {
pf->flags = I40E_FLAG_HW_ATR_EVICT_CAPABLE;
}

What do you think?

Thanks!
--
Gustavo A. R. Silva