[PATCH v6 2/2] net/ixgbe: Fix SFP detection and linking on hotplug

[Morten Brørup]

> From: Wang, Haiyue [mailto:haiyue.wang at intel.com]
> Sent: Wednesday, 13 April 2022 04.47
> To: Daly, Jeff; dev at dpdk.org
> Cc: stable at dpdk.org; Stephen Douthit; Yang, Qiming
> 
> > From: Jeff Daly <jeffd at silicom-usa.com>
> > Sent: Wednesday, April 13, 2022 01:42
> > To: dev at dpdk.org
> > Cc: stable at dpdk.org; Stephen Douthit <stephend at silicom-usa.com>;
> Wang, Haiyue <haiyue.wang at intel.com>
> >
> > Currently the ixgbe driver does not ID any SFP except for the first
> one
> > plugged in. This can lead to no-link, or incorrect speed conditions.
> >
> > For example:
> >
> > * If link is initially established with a 1G SFP, and later a 1G/10G
> > multispeed part is later installed, then the MAC link setup functions
> are
> > never called to change from 1000BASE-X to 10GBASE-R mode, and the
> link
> > stays running at the slower rate.
> >
> > * If link is initially established with a 1G SFP, and later a 10G
> only
> > module is later installed, no link is established, since we are still
> > trasnsmitting in 1000BASE-X mode to a 10GBASE-R only partner.
> >
> > Refactor the SFP ID/setup, and link setup code, to more closely match
> the
> > flow of the mainline kernel driver which does not have these issues.
> In
> > that driver a service task runs periodically to handle these
> operations
> > based on bit flags that have been set (usually via interrupt or
> userspace
> > request), and then get cleared once the requested subtask has been
> > completed.
> >
> > Fixes: af75078fece ("first public release")
> > Cc: stable at dpdk.org
> >
> 
> So BIG change for new platform, DON'T CC to stable!

What do you mean by "new platform"? The ixgbe hardware and driver is not new.

This patch fixes a bug (with a serious impact when occurring), so it should be backported. The size of the patch does not disqualify it for backporting.

-Morten