Re: [PATCH 1/2] net/fsl: fman: Allow fm_max_frame_sz & rx_extra_headroom config from devicetree.

[EVS Hardware Dpt <hardware.evs@gmail.com>]

Hi Madalin, Guys,

I didn't have that historical part in mind. So, even if I still think there
are a lot of examples super close to what I'm proposing everywhere in
dts files, devicetree is out of equation.

Could I change the patchset to allow configuration of those two parameters
from config ? I won't remove configuration using module parameters,
just adding (what I think to be) an easier way of configuration.

What do you think?

Regards,
Fred.

Le ven. 18 févr. 2022 à 12:33, Madalin Bucur <madalin.bucur@nxp.com> a écrit :
>
> > -----Original Message-----
> > From: EVS Hardware Dpt <hardware.evs@gmail.com>
> > Subject: Re: [PATCH 1/2] net/fsl: fman: Allow fm_max_frame_sz &
> > rx_extra_headroom config from devicetree.
> >
> > Hi Madalin, Guys
> >
> > I know, but it's somewhat difficult to use those parameters on kernel's
> > command line.
> > I don't think it's wrong to also add that in devicetree.
> > No removal, just an added feature.
> >
> > For ethernet node in devicetree, there are a lot of configuration stuff
> > like
> > max-frame-size to allow configuration of MTU
> > (and so potentially enable jumbo) and it's regarded as fine.
> >
> > It's also the goal of this patch. Allow an easy configuration of
> > fsl_fm_max_frm from a dts. I added rx_extra_headroom for the sake of
> > completeness.
> >
> > So I plead for this addition because I don't think it's wrong to do that
> > and
> > I consider it's nicer to add an optional devicetree property rather than
> > adding a lot of obscure stuff on kernel's command line.
> >
> > Hope you'll share my point of view.
> >
> > Have a nice weekend Madalin, Guys,
> > Fred.
>
> Hi, Fred,
>
> I understand your concerns in regards to usability but the device trees, as
> explained earlier by Jakub, have a different role - they describe the HW,
> rather than configure the SW on it. Removal of such config entries from the
> device tree was one item on a long list to get the DPAA drivers upstreamed.
>
> > Le ven. 18 févr. 2022 à 08:23, Madalin Bucur <madalin.bucur@nxp.com> a
> > écrit :
> > >
> > > > -----Original Message-----
> > > > From: Fred Lefranc <hardware.evs@gmail.com>
> > > > Subject: [PATCH 1/2] net/fsl: fman: Allow fm_max_frame_sz &
> > > > rx_extra_headroom config from devicetree.
> > > >
> > > > Allow modification of two additional Frame Manager parameters :
> > > > - FM Max Frame Size : Can be changed to a value other than 1522
> > > >   (ie support Jumbo Frames)
> > > > - RX Extra Headroom
> > > >
> > > > Signed-off-by: Fred Lefranc <hardware.evs@gmail.com>
> > >
> > > Hi, Fred,
> > >
> > > there are module params already for both, look into
> > >
> > > drivers/net/ethernet/freescale/fman/fman.c
> > >
> > > for fsl_fm_rx_extra_headroom and fsl_fm_max_frm.
> > >
> > > Regards,
> > > Madalin