Hi Bruce, > -----Original Message----- > From: Richardson, Bruce > Sent: Wednesday, February 24, 2016 10:26 PM > To: He, Shaopeng > Cc: Lu, Wenzhuo; dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH v2] ixgbe: fix link down issue on x550em_x > > On Thu, Feb 04, 2016 at 06:21:04AM +0000, He, Shaopeng wrote: > > > > > -----Original Message----- > > > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Wenzhuo Lu > > > Sent: Monday, February 01, 2016 4:43 PM > > > To: dev at dpdk.org > > > Subject: [dpdk-dev] [PATCH v2] ixgbe: fix link down issue on > > > x550em_x > > > > > > Normally the auto-negotiation is supported by FW. But on > > > X550EM_X_10G_T it's not supported by FW. As the port of > > > X550EM_X_10G_T is 10G. If we connect the port with a peer which is > > > 1G. The link is always down. > > > We have to supprted auto-neg by SW to avoid such link down issue. > > > > > > Signed-off-by: Wenzhuo Lu <wenzhuo.lu at intel.com> > > Acked-by: Shaopeng He <shaopeng.he at intel.com> > > > I'm a bit confused regarding the commit message and the code in the patch. > The commit message talks about enabling speed auto-negotiation, while the > code never refers to any such thing. Instead all we have are settings for > manipulating interrupt masks to enable PHY interrupts. I think some additional > information is needed to connect A and B together here. The reason is that the handler of the link speed auto-neg is already in the base code. It's ixgbe_handle_lasi. What we need is a trigger. When the advertised link speed changes, a PHY interruption will be triggered. So, we should handle this interruption and call ixgbe_handle_lasi to set the link speed correct. Let me add more explanation in the commit log.
> > A second, more minor nit is that the commit title never refers to link auto- > negotiation, but refers to this as a bug fix - which is also correct. If this > is > primarily a bug fix, please include a fixes line if possible, but please also > refer to > auto-neg in the title if possible too. I didn't add a fixes line because it doesn't fix an issue introduced by SW, or even FW, HW. As said in commit log, we hit a link down issue, but the root cause is the link speed auto-neg is not supported on this specific NIC. On the other NICs, link speed auto-neg is supported by FW, SW need no do anything. So we didn't implement the link speed auto-neg. But we have to implement this feature on this NIC for FW doesn't implement it. Should I change the tittle to "support link speed auto-neg on x550em_x"? > > /Bruce
