From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Dai Subject: [PATCH v9 5/5] doc: add description of the NIC reset API Date: Sun, 23 Jul 2017 17:15:13 +0800 Message-ID: <1500801313-25429-6-git-send-email-wei.dai@intel.com> References: <1500304503-41592-1-git-send-email-wei.dai@intel.com> <1500801313-25429-1-git-send-email-wei.dai@intel.com> Cc: dev@dpdk.org, Wei Dai To: thomas@monjalon.net, wenzhuo.lu@intel.com, konstantin.ananyev@intel.com, jingjing.wu@intel.com, beilei.xing@intel.com Return-path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 6D0C6325D for ; Sun, 23 Jul 2017 11:26:33 +0200 (CEST) In-Reply-To: <1500801313-25429-1-git-send-email-wei.dai@intel.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" This patch add the description of NIC reset API in doc/guides/prog_guide/poll_mode_drv.rst . It explains why this API is needed, when it should be called and some noticeable information. Signed-off-by: Wei Dai Reviewed-by: Remy Horton --- doc/guides/prog_guide/poll_mode_drv.rst | 41 +++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/doc/guides/prog_guide/poll_mode_drv.rst b/doc/guides/prog_guide/poll_mode_drv.rst index 1ac8f7e..7c95b3e 100644 --- a/doc/guides/prog_guide/poll_mode_drv.rst +++ b/doc/guides/prog_guide/poll_mode_drv.rst @@ -536,3 +536,44 @@ call. As an end result, the application is able to achieve its goal of monitoring a single statistic ("rx_errors" in this case), and if that shows packets being dropped, it can easily retrieve a "set" of statistics using the IDs array parameter to ``rte_eth_xstats_get_by_id`` function. + +NIC Reset API +~~~~~~~~~~~~~ + +.. code-block:: c + + int rte_eth_dev_reset(uint8_t port_id); + +Sometimes a port has to be reset passively. For example when a PF is +reset, all its VFs should also be reset by the application to make them +consistent with the PF. A DPDK application also can call this function +to trigger a port reset. Normally, a DPDK application would invokes this +function when an RTE_ETH_EVENT_INTR_RESET event is detected. + +It is the duty of the PMD to trigger RTE_ETH_EVENT_INTR_RESET events and +the application should register a callback function to handle these +events. When a PMD needs to trigger a reset, it can trigger an +RTE_ETH_EVENT_INTR_RESET event. On receiving an RTE_ETH_EVENT_INTR_RESET +event, applications can handle it as follows: Stop working queues, stop +calling Rx and Tx functions, and then call rte_eth_dev_reset( ). For +thread safety all these operations should be called from the same thread. + +For example when PF is reset, the PF sends a message to notify VFs of +this event and also trigger an interrupt to VFs. Then in the interrupt +service routine the VFs detects this notification message and calls +_rte_eth_dev_callback_process(dev, RTE_ETH_EVENT_INTR_RESET, NULL, +NULL). This means that a PF reset triggers an RTE_ETH_EVENT_INTR_RESET +event within VFs. The function _rte_eth_dev_callback_process( ) will +call the registered callback function. The callback function can trigger +the application to handle all operations the VF reset requires including +stopping Rx/Tx queues and calling rte_eth_dev_reset(). + +The rte_eth_dev_reset( ) itself is a generic function which only does +some hardware reset operations through calling dev_unint() and +dev_init(), and itself does not handle synchronization, which is handled +by application. + +The PMD itself should not call rte_eth_dev_reset( ). The PMD can trigger +the application to handle reset event. It is duty of application to +handle all synchronization before it calls rte_eth_dev_reset( ). + -- 2.7.5