Re: [dpdk-dev] [PATCH v2 1/2] app/testpmd: add link speed check before port start

["Li, Xiaoyun" <xiaoyun.li@intel.com>]

> -----Original Message-----
> From: Huisong Li <lihuisong@huawei.com>
> Sent: Friday, April 30, 2021 12:04
> To: Li, Xiaoyun <xiaoyun.li@intel.com>
> Cc: Yigit, Ferruh <ferruh.yigit@intel.com>; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v2 1/2] app/testpmd: add link speed check
> before port start
> 
> 
> 在 2021/4/30 11:19, Li, Xiaoyun 写道:
> >> -----Original Message-----
> >> From: Min Hu (Connor) <humin29@huawei.com>
> >> Sent: Wednesday, April 28, 2021 16:37
> >> To: dev@dpdk.org
> >> Cc: Yigit, Ferruh <ferruh.yigit@intel.com>; Li, Xiaoyun
> >> <xiaoyun.li@intel.com>
> >> Subject: [PATCH v2 1/2] app/testpmd: add link speed check before port
> >> start
> >>
> >> From: Huisong Li <lihuisong@huawei.com>
> >>
> >> Currently, to check whether the configured link_speeds is valid, we
> >> have to run "port start". In addition, if the configuration fails, "port-
> >dev_conf.link_speeds"
> >> maintained in testpmd cannot be restored.
> >>
> >> This patch adds the link_speeds check before port start by calling
> >> dev_configure, and resolves these problems.
> > Not sure about this patch. I don't think you can fix the issue you mentioned.
> > Probably only hns3 does speed check in dev_configure. I don't see this in other
> drivers, not in i40e/ice/mlx.
> > I guess it's because if it's not supported speed, it will just be UNKNOWN and
> user can config again?
> 
> I think that the validity of the configuration delivered by dev_configure is
> ensured by this interface and cannot be left to the backend.
> 
> Because it facilitates users to handle abnormal configurations in a timely
> manner. It may be more appropriate for the driver to do this check in
> dev_configure.

I still think it's not necessary.

> 
> In addition, even if other drivers do not add this check in dev_configure, this
> patch does not seem to affect the current behavior of these drivers.
> 
> > BTW, even if this behavior is accepted by others, still some comments below.
> >
> >> Signed-off-by: Huisong Li <lihuisong@huawei.com>
> >> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
> >> ---
> >>   app/test-pmd/cmdline.c | 42
> >> ++++++++++++++++++++++++++++++++++++++++-
> >> -
> >>   1 file changed, 40 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c index
> >> 5fdcc1c..ddbc629 100644
> >> --- a/app/test-pmd/cmdline.c
> >> +++ b/app/test-pmd/cmdline.c
> >> @@ -1549,8 +1549,12 @@ cmd_config_speed_all_parsed(void
> *parsed_result,
> >>   			__rte_unused void *data)
> >>   {
> >>   	struct cmd_config_speed_all *res = parsed_result;
> >> +	uint32_t old_link_speeds[RTE_MAX_ETHPORTS];
> >> +	struct rte_port *port;
> >>   	uint32_t link_speed;
> >>   	portid_t pid;
> >> +	portid_t i;
> >> +	int ret;
> >>
> >>   	if (!all_ports_stopped()) {
> >>   		printf("Please stop all ports first\n"); @@ -1562,7 +1566,26 @@
> >> cmd_config_speed_all_parsed(void *parsed_result,
> >>   		return;
> >>
> >>   	RTE_ETH_FOREACH_DEV(pid) {
> >> -		ports[pid].dev_conf.link_speeds = link_speed;
> >> +		port = &ports[pid];
> >> +		old_link_speeds[pid] = port->dev_conf.link_speeds;
> >> +		port->dev_conf.link_speeds = link_speed;
> >> +		ret = rte_eth_dev_configure(pid, nb_rxq, nb_txq,
> >> +					    &port->dev_conf);
> >> +		if (ret < 0) {
> >> +			printf("Failed to check link speeds for port %d, ret
> >> = %d.\n",
> >> +				pid, ret);
> >> +			goto roolback;
> > Why don't you just add restoring all ports speed here and then "break"? No
> matter one dev fails or not, all ports will do reconfig from your code logic.
> > And you type rollback wrongly.
> 
> It cannot exit directly after restoring all ports speed. If the cmd fails to execute,
> it is necessary to reconfigure device with the correct configuration.
>   Because "nb_rx/tx_queues" in dev->data are cleared to zero if dev_configure
> fails to be executed in PMD driver.

?
cmd_reconfig_device_queue(RTE_PORT_ALL, 1, 1); is at the end of this cmd. This will re-config all ports.
I don't understand why can't you add a restoring in this if and break this loop and do this reconfig.

> 
> >> +		}
> >> +	}
> >> +
> >> +	cmd_reconfig_device_queue(RTE_PORT_ALL, 1, 1);
> >> +
> >> +	return;
> >> +
> >> +roolback:
> >> +	for (i = 0; i <= pid; i++) {
> >> +		port = &ports[i];
> >> +		port->dev_conf.link_speeds = old_link_speeds[i];
> >>   	}
> >>
> >>   	cmd_reconfig_device_queue(RTE_PORT_ALL, 1, 1); @@ -1621,7
> >> +1644,10 @@ cmd_config_speed_specific_parsed(void *parsed_result,
> >>   				__rte_unused void *data)
> >>   {
> >>   	struct cmd_config_speed_specific *res = parsed_result;
> >> +	uint32_t old_link_speeds;
> >> +	struct rte_port *port;
> >>   	uint32_t link_speed;
> >> +	int ret;
> >>
> >>   	if (!all_ports_stopped()) {
> >>   		printf("Please stop all ports first\n"); @@ -1635,8 +1661,20 @@
> >> cmd_config_speed_specific_parsed(void *parsed_result,
> >>   			&link_speed) < 0)
> >>   		return;
> >>
> >> -	ports[res->id].dev_conf.link_speeds = link_speed;
> >> +	port = &ports[res->id];
> >> +	old_link_speeds = port->dev_conf.link_speeds;
> >> +	port->dev_conf.link_speeds = link_speed;
> >> +	ret = rte_eth_dev_configure(res->id, nb_rxq, nb_txq,
> >> +				    &port->dev_conf);
> >> +	if (ret < 0) {
> >> +		printf("Failed to check link speeds for port %d, ret = %d.\n",
> >> +			res->id, ret);
> >> +		port->dev_conf.link_speeds = old_link_speeds;
> >> +	}
> >>
> >> +	/*
> >> +	 * If the cmd fails to execute, it is necessary to reconfigure device.
> >> +	 */
> >>   	cmd_reconfig_device_queue(RTE_PORT_ALL, 1, 1);  }
> >>
> >> --
> >> 2.7.4
> > .