* @return
* - 0: Success, receive queue correctly set up.
* - -EIO: if device is removed.
- * - -EINVAL: The size of network buffers which can be allocated from the
- * memory pool does not fit the various buffer sizes allowed by the
- * device controller.
+ * - -EINVAL: The memory pool pointer is null or the size of network buffers
+ * which can be allocated from this memory pool does not fit the various
+ * buffer sizes allowed by the device controller.
* - -ENOMEM: Unable to allocate the receive ring descriptors or to
* allocate network memory buffers from the memory pool when
* initializing receive descriptors.
* .nb_max = UINT16_MAX,
* .nb_min = 0,
* .nb_align = 1,
+ * .nb_seg_max = UINT16_MAX,
+ * .nb_mtu_seg_max = UINT16_MAX,
* };
*
* device = dev->device
*/
int rte_eth_timesync_write_time(uint16_t port_id, const struct timespec *time);
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Read the current clock counter of an Ethernet device
+ *
+ * This returns the current raw clock value of an Ethernet device. It is
+ * a raw amount of ticks, with no given time reference.
+ * The value returned here is from the same clock than the one
+ * filling timestamp field of Rx packets when using hardware timestamp
+ * offload. Therefore it can be used to compute a precise conversion of
+ * the device clock to the real time.
+ *
+ * E.g, a simple heuristic to derivate the frequency would be:
+ * uint64_t start, end;
+ * rte_eth_read_clock(port, start);
+ * rte_delay_ms(100);
+ * rte_eth_read_clock(port, end);
+ * double freq = (end - start) * 10;
+ *
+ * Compute a common reference with:
+ * uint64_t base_time_sec = current_time();
+ * uint64_t base_clock;
+ * rte_eth_read_clock(port, base_clock);
+ *
+ * Then, convert the raw mbuf timestamp with:
+ * base_time_sec + (double)(mbuf->timestamp - base_clock) / freq;
+ *
+ * This simple example will not provide a very good accuracy. One must
+ * at least measure multiple times the frequency and do a regression.
+ * To avoid deviation from the system time, the common reference can
+ * be repeated from time to time. The integer division can also be
+ * converted by a multiplication and a shift for better performance.
+ *
+ * @param port_id
+ * The port identifier of the Ethernet device.
+ * @param clock
+ * Pointer to the uint64_t that holds the raw clock value.
+ *
+ * @return
+ * - 0: Success.
+ * - -ENODEV: The port ID is invalid.
+ * - -ENOTSUP: The function is not supported by the Ethernet driver.
+ */
+int __rte_experimental
+rte_eth_read_clock(uint16_t port_id, uint64_t *clock);
+
/**
* Config l2 tunnel ether type of an Ethernet device for filtering specific
* tunnel packets by ether type.