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doc: net: Enhance 802.1Qav documentation

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There was no examples how to set the Qav parameters from application.

Fixes #21074

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
This commit is contained in:
Jukka Rissanen 2019-11-29 10:57:46 +02:00 • committed by David Leach
commit 38db500fe5
1 changed files with 92 additions and 0 deletions
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92
doc/reference/networking/8021Qav.rst
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@ -13,5 +13,97 @@ described in the `IEEE 802.1Qav-2009 standard`_. Zephyr does not
implement the actual shaper; it only provides a way to configure the
shaper implemented by the Ethernet device driver.
Enabling 802.1Qav
*****************
To enable 802.1Qav shaper, the Ethernet device driver must declare
that it supports credit-based shaping. The Ethernet driver's capability
function must return ``ETHERNET_QAV`` value for this purpose. Typically
also priority queues ``ETHERNET_PRIORITY_QUEUES`` need to be supported.
.. code-block:: none
static enum ethernet_hw_caps eth_get_capabilities(struct device *dev)
{
ARG_UNUSED(dev);
return ETHERNET_QAV | ETHERNET_PRIORITY_QUEUES |
ETHERNET_HW_VLAN | ETHERNET_LINK_10BASE_T |
ETHERNET_LINK_100BASE_T;
}
See ``sam-e70-xplained`` board Ethernet driver
:zephyr_file:`drivers/ethernet/eth_sam_gmac.c` for an example.
Configuring 802.1Qav
********************
The application can configure the credit-based shaper like this:
.. code-block:: c
#include <net/net_if.h>
#include <net/ethernet.h>
#include <net/ethernet_mgmt.h>
static void qav_set_status(struct net_if *iface,
int queue_id, bool enable)
{
struct ethernet_req_params params;
int ret;
memset(&params, 0, sizeof(params));
params.qav_param.queue_id = queue_id;
params.qav_param.enabled = enable;
params.qav_param.type = ETHERNET_QAV_PARAM_TYPE_STATUS;
/* Disable or enable Qav for a queue */
ret = net_mgmt(NET_REQUEST_ETHERNET_SET_QAV_PARAM,
iface, &params,
sizeof(struct ethernet_req_params));
if (ret) {
LOG_ERR("Cannot %s Qav for queue %d for interface %p",
enable ? "enable" : "disable",
queue_id, iface);
}
}
static void qav_set_bandwidth_and_slope(struct net_if *iface,
int queue_id,
unsigned int bandwidth,
unsigned int idle_slope)
{
struct ethernet_req_params params;
int ret;
memset(&params, 0, sizeof(params));
params.qav_param.queue_id = queue_id;
params.qav_param.delta_bandwidth = bandwidth;
params.qav_param.type = ETHERNET_QAV_PARAM_TYPE_DELTA_BANDWIDTH;
ret = net_mgmt(NET_REQUEST_ETHERNET_SET_QAV_PARAM,
iface, &params,
sizeof(struct ethernet_req_params));
if (ret) {
LOG_ERR("Cannot set Qav delta bandwidth %u for "
"queue %d for interface %p",
bandwidth, queue_id, iface);
}
params.qav_param.idle_slope = idle_slope;
params.qav_param.type = ETHERNET_QAV_PARAM_TYPE_IDLE_SLOPE;
ret = net_mgmt(NET_REQUEST_ETHERNET_SET_QAV_PARAM,
iface, &params,
sizeof(struct ethernet_req_params));
if (ret) {
LOG_ERR("Cannot set Qav idle slope %u for "
"queue %d for interface %p",
idle_slope, queue_id, iface);
}
}
.. _IEEE 802.1Qav-2009 standard:
https://standards.ieee.org/standard/802_1Qav-2009.html