Hello Karicheri, Muralidharan,
The patch 84640e27f230: "net: netcp: Add Keystone NetCP core ethernet
driver" from Jan 15, 2015, leads to the following static checker
warning:
drivers/net/ethernet/ti/netcp_core.c:1599 netcp_setup_navigator_resources()
warn: passing zero to 'PTR_ERR'
drivers/net/ethernet/ti/netcp_core.c
1583 static int netcp_setup_navigator_resources(struct net_device *ndev)
1584 {
1585 struct netcp_intf *netcp = netdev_priv(ndev);
1586 struct knav_queue_notify_config notify_cfg;
1587 struct knav_dma_cfg config;
1588 u32 last_fdq = 0;
1589 u8 name[16];
1590 int ret;
1591 int i;
1592
1593 /* Create Rx/Tx descriptor pools */
1594 snprintf(name, sizeof(name), "rx-pool-%s", ndev->name);
1595 netcp->rx_pool = knav_pool_create(name, netcp->rx_pool_size,
1596 netcp->rx_pool_region_id);
1597 if (IS_ERR_OR_NULL(netcp->rx_pool)) {
1598 dev_err(netcp->ndev_dev, "Couldn't create rx pool\n");
1599 ret = PTR_ERR(netcp->rx_pool);
1600 goto fail;
1601 }
1602
1603 snprintf(name, sizeof(name), "tx-pool-%s", ndev->name);
1604 netcp->tx_pool = knav_pool_create(name, netcp->tx_pool_size,
1605 netcp->tx_pool_region_id);
1606 if (IS_ERR_OR_NULL(netcp->tx_pool)) {
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Assume this is NULL.
When a function returns a mix of error pointers and NULL that means the
the feature can be disabled. Like an error pointer is straight forward,
it means that something is broken. But a NULL just means the feature is
disabled so it's not an error but we also don't have a pointer to the
feature because it doesn't exist.
In this case, how can the driver function without memory pools? It
doesn't make sense that the user should be able to disable it.
1607 dev_err(netcp->ndev_dev, "Couldn't create tx pool\n");
If it's not an error, we shouldn't print an error message.
1608 ret = PTR_ERR(netcp->tx_pool);
PTR_ERR(NULL) is zero/success.
1609 goto fail;
1610 }
1611
This driver mentions ERR_PTR_OR_NULL() a lot but all the mentions I saw
were wrong. :( I can't compile the driver myself or I would send a
patch.
regards,
dan carpenter
