> -----Original Message----- > From: Edwin Peer <edwin.p...@broadcom.com> > Sent: Sunday, January 31, 2021 7:39 PM > To: Danielle Ratson <daniel...@nvidia.com> > Cc: Michal Kubecek <mkube...@suse.cz>; netdev <netdev@vger.kernel.org>; David > S . Miller <da...@davemloft.net>; Jakub > Kicinski <k...@kernel.org>; Jiri Pirko <j...@nvidia.com>; Andrew Lunn > <and...@lunn.ch>; f.faine...@gmail.com; mlxsw > <ml...@nvidia.com>; Ido Schimmel <ido...@nvidia.com> > Subject: Re: [PATCH net-next v3 2/7] ethtool: Get link mode in use instead of > speed and duplex parameters > > On Sun, Jan 31, 2021 at 7:33 AM Danielle Ratson <daniel...@nvidia.com> wrote: > > > Edwin, adding the a new parameter requires a new patchset in my opinion. > > Implementing the symmetrical side of the link_mode get, however can be a > > part of this set. But, the problem with that would be that, as Michal said, > > speed lanes and duplex can't provide us a single link_mode because of the > > media. And since link_mode is one bit parameter, passing it to the driver > > while randomly choosing the media, may cause either information loss, or > > even fail to sync on a link mode if the chosen media is specifically not > > supported in the lower levels. So, in my opinion it is related to adding the > > new parameter we discussed, and should be done in a separate set. > > Media is a little special in the sense that it physically depends on > what's plugged in. In that sense, media is truly read only. Setting it > won't change what's plugged in, so not having a separate knob for it > is probably okay, as it can be inferred from the active link mode on > the query side. > > I don't see why the driver can't error if asked to set a link mode > having an incompatible media? The link modes corresponding to media > that's not plugged in wouldn't be listed in the supported set, so > there's no reason the user should expect to be able to set those. > There's no ambiguity or information loss if you refuse to set modes > that don't have the matching media attached. > > Regards, > Edwin Peer
Ok, ill send another version with the symmetrical side. Ethtool will try to compose a supported link_mode from the parameters from user space and will choose randomly between the supported ones. Sounds ok? Thanks, Danielle
