RE: [PATCH v3] net/ixgbe: Retry SFP ID read field to handle misbehaving SFPs

["Zhang, Qi Z" <qi.z.zhang@intel.com>]

> -----Original Message-----
> From: Wang, Haiyue <haiyue.wang@intel.com>
> Sent: Thursday, March 24, 2022 9:01 AM
> To: Daly, Jeff <jeffd@silicom-usa.com>; dev@dpdk.org
> Cc: Stephen Douthit <stephend@silicom-usa.com>; Daly, Jeff
> <jeffd@silicom-usa.com>
> Subject: RE: [PATCH v3] net/ixgbe: Retry SFP ID read field to handle
> misbehaving SFPs

Slightly reword the title as below to fix check-git-log warning

net/ixgbe: retry to handle misbehaving SFPs read


> 
> > -----Original Message-----
> > From: jeffd@silicom-usa.com <jeffd@silicom-usa.com>
> > Sent: Thursday, March 24, 2022 04:04
> > To: dev@dpdk.org
> > Cc: Stephen Douthit <stephend@silicom-usa.com>; Daly, Jeff
> > <jeffd@silicom-usa.com>; Wang, Haiyue <haiyue.wang@intel.com>
> > Subject: [PATCH v3] net/ixgbe: Retry SFP ID read field to handle
> > misbehaving SFPs
> >
> > From: Stephen Douthit <stephend@silicom-usa.com>
> >
> > Some XGS-PON SFPs have been observed ACKing I2C reads and returning
> > uninitialized garbage while their uC boots.  This can lead to the SFP
> > ID code marking an otherwise working SFP module as unsupported if a
> > bogus ID value is read while its internal PHY/microcontroller is still
> > booting.
> >
> > Retry the ID read several times looking not just for NAK, but also for
> > a valid ID field.
> >
> > Since the device isn't NAKing the trasanction the existing longer
> > retry code in ixgbe_read_i2c_byte_generic_int() doesn't apply here.
> >
> > Signed-off-by: Stephen Douthit <stephend@silicom-usa.com>
> > Signed-off-by: Jeff Daly <jeffd@silicom-usa.com>
> > ---
> >
> > Notes:
> >     v2:
> >     * Removed superfluous DEBUGOUT
> >     * Renamed id_reads to retries
> >     * Don't assume status == 0 means IXGBE_SUCCESS
> >
> >     v3:
> >     * Removed extra braces around single statement if
> >
> >  drivers/net/ixgbe/base/ixgbe_phy.c | 27 ++++++++++++++++++++++++--
> -
> >  1 file changed, 24 insertions(+), 3 deletions(-)
> >
> 
> Thanks!
> 
> Reviewed-by: Haiyue Wang <haiyue.wang@intel.com>

Applied to dpdk-next-net-intel.

Thanks
Qi
> 
> > --
> > 2.25.1