Hi Harry, You are correct, multiple structs with dev_infos_get defined in them caused me to jump to wrong implementation.
Still a bit "wrong" that comment for eventdev_info_get_t for event setup states returns 0 on success. Using older version of https://github.com/Xilinx/dma_ip_drivers/tree/master/QDMA/DPDK targeting dpdk-19.11 for a corporate internal project as such can't give much details. That version had a issue with no return statements in the infos_get function which was causing me issues. Br, Fredrik -----Original Message----- From: Van Haaren, Harry <harry.van.haa...@intel.com> Sent: den 1 februari 2021 10:44 To: Fredrik A Lindgren <fredrik.a.lindg...@tieto.com>; dev@dpdk.org Subject: RE: Question: typedef of eventdev_info_get_t bug? > -----Original Message----- > From: dev <dev-boun...@dpdk.org> On Behalf Of Fredrik A Lindgren > Sent: Monday, February 1, 2021 9:22 AM > To: dev@dpdk.org > Subject: [dpdk-dev] Question: typedef of eventdev_info_get_t bug? > > While debugging a driver I was looking at the code and realized that > eventdev_info_get_t typedef is defined with void return value but > documentation for it says it should return 0 Hi Fredrik, Be aware that your snippets of code below is mixing Event-dev and Eth-dev. This is likely the cause of confusion. > lib/librte_eventdev/eventdev_pmd.h: > > ... > * @return > * Returns 0 on success > */ > typedef void (*eventdev_info_get_t)(struct rte_eventdev *dev, > struct > rte_event_dev_info *dev_info); ... > struct rte_eventdev_ops { > eventdev_info_get_t dev_infos_get; > /**< Get device info. */ > ... > > While return value from it is used in lib/librte_ethdev/rte_ethdev.c: > > int > rte_eth_dev_info_get(uint16_t port_id, struct rte_eth_dev_info > *dev_info) ... > diag = (*dev->dev_ops->dev_infos_get)(dev, dev_info); > if (diag != 0) { > ... At the Eventdev layer, info_get() can return int (particularly 0 on success, or -ERROR values). At the Eventdev PMD layer, info_get() has a return void (the PMD cannot indicate failure on providing its info) Hence, the info_get() typedef (for the PMD) is void, but the Eventdev layer itself checks some dev_id values etc, and can return -EINVAL or -ENOTSUP in case the PMD doesn't support info_get(). > Driver I'm debugging doesn't have any return statement in it's > dev_infos_get function which seems to cause it to have "result" of > last operation done in that function as return value. > Though this behavior may be compiler specific but it should probably > be clarified and updated (change prototype of stop using return value) to > avoid issue with it. Perhaps provide some more detail on Eventdev/Ethdev that you're debugging a driver on, provide some links to specific parts of the code? It seems like (from Eventdev anyway) its meant to work this way. > Br, > Fredrik Regards, -Harry
