Re: [dpdk-dev] [PATCH] ixgbe: fix build with gcc 4.4

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: Vlad Zolotarov [mailto:vladz@cloudius-systems.com]
> Sent: Tuesday, April 14, 2015 1:49 PM
> To: Thomas Monjalon; Ananyev, Konstantin; Zhang, Helin
> Cc: dev@dpdk.org
> Subject: Re: [PATCH] ixgbe: fix build with gcc 4.4
> 
> 
> 
> On 04/14/15 12:31, Thomas Monjalon wrote:
> > With GCC 4.4.7 from CentOS 6.5, the following errors arise:
> >
> > lib/librte_pmd_ixgbe/ixgbe_rxtx.c: In function ‘ixgbe_dev_rx_queue_setup’:
> > lib/librte_pmd_ixgbe/ixgbe_rxtx.c:2509: error: missing initializer
> > lib/librte_pmd_ixgbe/ixgbe_rxtx.c:2509: error: (near initialization for ‘dev_info.driver_name’)
> >
> > lib/librte_pmd_ixgbe/ixgbe_rxtx.c: In function ‘ixgbe_set_rsc’:
> > lib/librte_pmd_ixgbe/ixgbe_rxtx.c:4072: error: missing initializer
> > lib/librte_pmd_ixgbe/ixgbe_rxtx.c:4072: error: (near initialization for ‘dev_info.driver_name’)
> >
> > lib/librte_pmd_ixgbe/ixgbe_rxtx.c: In function ‘ixgbe_recv_pkts_lro_single_alloc’:
> > lib/librte_pmd_ixgbe/ixgbe_rxtx.c:1479: error: ‘next_rsc_entry’ may be used uninitialized in this function
> > lib/librte_pmd_ixgbe/ixgbe_rxtx.c:1480: error: ‘next_rxe’ may be used uninitialized in this function
> >
> > Fixes: 8eecb3295aed ("ixgbe: add LRO support")
> >
> > Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>
> > ---
> >   lib/librte_pmd_ixgbe/ixgbe_rxtx.c | 8 ++++----
> >   1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> > index f1da9ec..a2b8631 100644
> > --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> > +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> > @@ -1476,8 +1476,8 @@ ixgbe_recv_pkts_lro(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts,
> >   		bool eop;
> >   		struct ixgbe_rx_entry *rxe;
> >   		struct ixgbe_rsc_entry *rsc_entry;
> > -		struct ixgbe_rsc_entry *next_rsc_entry;
> > -		struct ixgbe_rx_entry *next_rxe;
> > +		struct ixgbe_rsc_entry *next_rsc_entry = NULL;
> > +		struct ixgbe_rx_entry *next_rxe = NULL;
> >   		struct rte_mbuf *first_seg;
> >   		struct rte_mbuf *rxm;
> >   		struct rte_mbuf *nmb;
> > @@ -2506,7 +2506,7 @@ ixgbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
> >   	struct ixgbe_rx_queue *rxq;
> >   	struct ixgbe_hw     *hw;
> >   	uint16_t len;
> > -	struct rte_eth_dev_info dev_info = { 0 };
> > +	struct rte_eth_dev_info dev_info = { .max_rx_queues = 0 };
> >   	struct rte_eth_rxmode *dev_rx_mode = &dev->data->dev_conf.rxmode;
> >   	bool rsc_requested = false;
> >
> > @@ -4069,7 +4069,7 @@ ixgbe_set_rsc(struct rte_eth_dev *dev)
> >   {
> >   	struct rte_eth_rxmode *rx_conf = &dev->data->dev_conf.rxmode;
> >   	struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> > -	struct rte_eth_dev_info dev_info = { 0 };
> > +	struct rte_eth_dev_info dev_info = { .max_rx_queues = 0 };
> 
> Hmmm... Unless I miss something this and one above would zero only a
> single field - "max_rx_queues"; and would leave the rest uninitialized.
> The original code intend to zero the whole struct. The alternative to
> the original lines could be usage of memset().

As I understand, in that case compiler had to set all non-explicitly initialised members to 0.
So I think we are ok here.
 
> 
> >   	bool rsc_capable = false;
> >   	uint16_t i;
> >   	uint32_t rdrxctl;