Re: [PATCH 1/2] rte_ethdev: update link status (speed, duplex, link_up) after rte_eth_dev_start

[Jia Yu <jyu-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>]

My answer to Helin¹s comments:

This patch is needed for bond slave devices or other devices, when LSC
interrupt is enabled.
 1. slave_configure()  -> slave_eth_dev->Š.lsc = 1

 2. rte_eth_link_get() reads dev_link from eth_dev, when lsc interrupt is
enabled. However, the dev_link on eth_dev has not be initialized and
showed link down state. This patch initializes the device¹s dev_link at
rte_eth_dev_start time.

Please let me know if you have further questions/comments.

Thanks,
Jia

On 1/30/15, 2:28 AM, "Thomas Monjalon" <thomas.monjalon-pdR9zngts4EAvxtiuMwx3w@public.gmane.org> wrote:

>Jia, any news on this patchset?
>
>2014-11-12 03:57, Zhang, Helin:
>> Hi Jia
>> 
>> > -----Original Message-----
>> > From: dev [mailto:dev-bounces-VfR2kkLFssw@public.gmane.org] On Behalf Of Jia Yu
>> > Sent: Saturday, November 8, 2014 1:32 AM
>> > To: dev-VfR2kkLFssw@public.gmane.org
>> > Subject: [dpdk-dev] [PATCH 1/2] rte_ethdev: update link status
>>(speed, duplex,
>> > link_up) after rte_eth_dev_start
>> > 
>> > Since LSR interrupt is disabled by pmd drivers, link status in
>>rte_eth_device is
>> > always down.
>> If LSC interrupt is disabled by default, it will poll the link status
>>during the initialization
>> or in dev_start, and then the link status should he correct. If I am
>>not wrong.
>> 
>> > Bond slave_configure() enables LSR interrupt on devices to get
>>notification if link
>> > status changes. However, the LSC interrupt at device start time is
>>still lost.
>> Before enabling interrupt for LSC, the link status should be polled. So
>>after the port
>> startup, the link status should be there.
>> 
>> > 
>> > In this fix, call link_update to read link status from hardware
>>register at device
>> > start time.
>> Could you help to explain this code changes a bit more? Why we need it?
>> 
>> > 
>> > Issue:
>> > Change-Id: Ib57a1c9114f922485c7b0f4338bfe7b3d3f87d65
>> > Signed-off-by: Jia Yu <jyu-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
>> > ---
>> >  lib/librte_ether/rte_ethdev.c | 4 ++++
>> >  1 file changed, 4 insertions(+)
>> > 
>> > diff --git a/lib/librte_ether/rte_ethdev.c
>>b/lib/librte_ether/rte_ethdev.c index
>> > ff1c769..6c01b02 100644
>> > --- a/lib/librte_ether/rte_ethdev.c
>> > +++ b/lib/librte_ether/rte_ethdev.c
>> > @@ -869,6 +869,10 @@ rte_eth_dev_start(uint8_t port_id)
>> > 
>> >  	rte_eth_dev_config_restore(port_id);
>> > 
>> > +	if (dev->data->dev_conf.intr_conf.lsc != 0) {
>> > +		FUNC_PTR_OR_ERR_RET(*dev->dev_ops->link_update, -ENOTSUP);
>> > +		(*dev->dev_ops->link_update)(dev, 0);
>> > +	}
>> >  	return 0;
>> >  }
>> > 
>> > --
>> > 1.9.1
>> 
>> Regards,
>> Helin
>