Hi, You forgot to Cc Andrew, co-maintainer of ethdev.
20/03/2019 05:54, Qi Zhang: > Device reset should be implemented in an async way since it is > possible to be invoked in interrupt thread and sometimes to reset a > device need to wait for some dependency, for example, a VF expects for > PF ready or a NIC function as part of a SOC wait for the whole system > reset complete, and all these time-consuming tasks will block the > interrupt thread. > The patch rename rte_eth_dev_reset to rte_eth_dev_reset_async and > rework the implementation. It will spawn a new thread which will call > ops->dev_reset, and when finished it will raise the event > RTE_ETH_EVENT_RESET_COMPLETE. The application should always wait for > this event before it continues to configure and restart the device. > > Signed-off-by: Qi Zhang <qi.z.zh...@intel.com> > --- > - * When this function is called, it first stops the port and then calls the > - * PMD specific dev_uninit( ) and dev_init( ) to return the port to initial > - * state, in which no Tx and Rx queues are setup, as if the port has been > - * reset and not started. The port keeps the port id it had before the > - * function call. > - * > - * After calling rte_eth_dev_reset( ), the application should use > - * rte_eth_dev_configure( ), rte_eth_rx_queue_setup( ), > - * rte_eth_tx_queue_setup( ), and rte_eth_dev_start( ) > - * to reconfigure the device as appropriate. > - * > - * Note: To avoid unexpected behavior, the application should stop calling > - * Tx and Rx functions before calling rte_eth_dev_reset( ). For thread > - * safety, all these controlling functions should be called from the same > - * thread. > + * @note > + * Device reset may have the dependency, for example, a VF reset expects > + * PF ready, or a NIC function as a part of a SOC need to wait for other > + * parts of the system be ready, these are time-consuming tasks and will > + * block current thread. > + * > + * As the name, rte_eth_dev_reset_async is an async API, it will spwan a > + * new thread to call ops->dev_reset, once it is finished, it will raise > + * the RTE_ETH_EVENT_RESET_COMPLETE event to notify application. That makes > + * things easy for an application that want to reset the device from the > + * interrupt thread since typically a RTE_ETH_EVENT_INTR_RESET handler is > + * invoked in interrupt thread. The typical implementation of ops->dev_reset > + * will do some hardware reset operations through calling dev_uninit() and > + * dev_init(). > + * > + * Application should not assume device reset is finished after > + * rte_eth_dev_reset_async return, it should always wait for a > + * RTE_ETH_EVENT_RESET_COMPLETE event and check the reset result. > + * If reset success, application should call rte_eth_dev_configure( ), > + * rte_eth_rx_queue_setup( ), rte_eth_tx_queue_setup( ), > + * and rte_eth_dev_start( ) to reconfigure the device as appropriate. > + * > + * @Note > + * To avoid unexpected behavior, the application should stop calling > + * Tx and Rx functions before calling rte_eth_dev_reset_async( ). > * > * @param port_id > * The port identifier of the Ethernet device. > @@ -1880,12 +1892,10 @@ void rte_eth_dev_close(uint16_t port_id); > * - (0) if successful. > * - (-EINVAL) if port identifier is invalid. > * - (-ENOTSUP) if hardware doesn't support this function. > - * - (-EPERM) if not ran from the primary process. > - * - (-EIO) if re-initialisation failed or device is removed. > * - (-ENOMEM) if the reset failed due to OOM. > - * - (-EAGAIN) if the reset temporarily failed and should be retried later. > + * - (<0) other errors from low level driver. > */ > -int rte_eth_dev_reset(uint16_t port_id); > +int rte_eth_dev_reset_async(uint16_t port_id); Sorry I didn't check whether this API is better or not, but I know it cannot be accepted before proposing a deprecation notice. Perhaps you may keep the old API and just add the new one. Honestly, I never really agreed with the purpose of the reset API. So making it async or not, I have no real opinion... ... but spawning a new thread at each function call, I feel it is bad.
