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

[Wang, Haiyue]

> -----Original Message-----
> From: Jeff Daly <jeffd at silicom-usa.com>
> Sent: Tuesday, April 19, 2022 05:55
> To: Wang, Haiyue <haiyue.wang at intel.com>; dev at dpdk.org
> Cc: stable at dpdk.org
> Subject: RE: [PATCH v6 2/2] net/ixgbe: Fix SFP detection and linking on hotplug
> 
> 
> 
> > -----Original Message-----
> > From: Wang, Haiyue <haiyue.wang at intel.com>
> > Sent: Thursday, April 14, 2022 8:11 AM
> > To: Jeff Daly <jeffd at silicom-usa.com>; dev at dpdk.org
> > Cc: stable at dpdk.org
> > Subject: RE: [PATCH v6 2/2] net/ixgbe: Fix SFP detection and linking on
> > hotplug
> >
> > Caution: This is an external email. Please take care when clicking links or
> > opening attachments.
> >
> >
> > > -----Original Message-----
> > > From: Jeff Daly <jeffd at silicom-usa.com>
> > > Sent: Thursday, April 14, 2022 18:41
> > > To: Wang, Haiyue <haiyue.wang at intel.com>; dev at dpdk.org
> > > Cc: stable at dpdk.org
> > > Subject: RE: [PATCH v6 2/2] net/ixgbe: Fix SFP detection and linking
> > > on hotplug
> > >
> > >
> > >
> > > > -----Original Message-----
> > > > From: Wang, Haiyue <haiyue.wang at intel.com>
> > > > Sent: Wednesday, April 13, 2022 11:00 PM
> > > > To: Jeff Daly <jeffd at silicom-usa.com>; dev at dpdk.org
> > > > Cc: stable at dpdk.org; Stephen Douthit <stephend at silicom-usa.com>
> > > > Subject: RE: [PATCH v6 2/2] net/ixgbe: Fix SFP detection and linking
> > > > on hotplug
> > > >
> > > > Caution: This is an external email. Please take care when clicking
> > > > links or opening attachments.
> > > >
> > > >
> > > > > -----Original Message-----
> > > > > From: Wang, Haiyue
> > > > > Sent: Thursday, April 14, 2022 10:49
> > > > > To: Jeff Daly <jeffd at silicom-usa.com>; dev at dpdk.org
> > > > > Cc: stable at dpdk.org; Stephen Douthit <stephend at silicom-usa.com>
> > > > > Subject: RE: [PATCH v6 2/2] net/ixgbe: Fix SFP detection and
> > > > > linking on hotplug
> > > > >
> > > > > > -----Original Message-----
> > > > > > 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>
> > > > > > Subject: [PATCH v6 2/2] net/ixgbe: Fix SFP detection and linking
> > > > > > on hotplug
> > > > > >
> > > > > > 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
> > > > > >
> > > > > > Signed-off-by: Stephen Douthit <stephend at silicom-usa.com>
> > > > > > Signed-off-by: Jeff Daly <jeffd at silicom-usa.com>
> > > > > > ---
> > > > > >  drivers/net/ixgbe/ixgbe_ethdev.c | 533
> > > > > > +++++++++++++++++++++++--------
> > > > > > +++++++++++++++++++++++drivers/net/ixgbe/ixgbe_ethdev.h |
> > > > > > 14 +-
> > > > > >  2 files changed, 410 insertions(+), 137 deletions(-)
> > > > > >
> > > > >
> > > > >
> > > > > >
> > > > > >  struct ixgbe_stat_mapping_registers { @@ -510,7 +509,7 @@
> > > > > > struct ixgbe_adapter {
> > > > > >     uint8_t pflink_fullchk;
> > > > > >     uint8_t mac_ctrl_frame_fwd;
> > > > > >     rte_atomic32_t link_thread_running;
> > > > > > -   pthread_t link_thread_tid;
> > > > > > +   pthread_t service_thread_tid;
> > > > >
> > > > > No need to rename this variable,
> > > >
> > > > Let's do link related service now, so we can keep it, I missed to
> > > > add my comment. ;-)
> > > >
> > >
> > > I don't understand this reply, are you still asking to rework the patch or
> > not?
> > >
> >
> > Different thing.
> >
> > 1. This var can be kept to trace the created thread. (change less code to keep
> >    the patch clean.)
> > 2. Yes, two patches.
> >
> 
> ok, I guess I'm just being thick-headed here, but I still don't understand why you are saying it
> should be split into
> 2 patches.  if I understand *what* you are asking, you're saying make the original thread periodic to
> continuously

Well, ...

Your patch merges the original 'ixgbe_setup_link' task into one,
this will make us hard to review the whole design. So what I said
is: firstly, let's change the thread to a service thread to handle
the 'ixgbe_setup_link' subtask firstly. Which is 'ixgbe_link_service'
in your whole patch.

Small patch is good for us to review, and try to do one thing.

Hope this time, I can make myself clear. ;-)

> do ixgbe_link_setup() ?  I believe the problem with the setup is that the sfp_type is only detected
> once
> at initialization time and if nothing is in the cage then the code just returns IXGBE_SUCCESS, in
> which case making
> this task periodic is useless.  the whole issue of hotplug is only addressed by the entire patch which
> 1) makes the
> task periodic, 2) changes the actions of the task to look for whether the cage has something in it and
> whether its
> been changed and needs to be configured again.
> 
> 
> > > > > we can separate this patch as least into two patches:
> > > >
> > > >
> > > > >
> > > > > 1st, change the thread handle 'ixgbe_dev_setup_link_thread_handler'
> > > > > from
> > > > >
> > > > > run-once to as periodical, to handle the original issue.
> > > > >
> > > > > The name 'ixgbe_dev_setup_link_thread_handler' may be not suitable
> > > > > now, as it is a service thread.
> > > > >
> > > > > We can change it to "'ixgbe_link_service_thread_handler'" to
> > > > > reflect the change purpose.
> > > > >
> > > > > 2nd, add the SFP hotplug in this patch.
> > > > >
> > > > >
> > > > >
> > > > > >  };
> > > > > >
> > > > > > --
> > > > > > 2.25.1