Re: [Patch v2 net-next 2/7] octeontx2-af: Add new CGX_CMD to get PHY FEC statistics

[Hariprasad Kelam]

Hi Willem,

> -----Original Message-----
> From: Willem de Bruijn <willemdebruijn.kernel@xxxxxxxxx>
> Sent: Saturday, January 30, 2021 7:57 PM
> To: Hariprasad Kelam <hkelam@xxxxxxxxxxx>
> Cc: Network Development <netdev@xxxxxxxxxxxxxxx>; LKML <linux-
> kernel@xxxxxxxxxxxxxxx>; David Miller <davem@xxxxxxxxxxxxx>; Jakub
> Kicinski <kuba@xxxxxxxxxx>; Sunil Kovvuri Goutham
> <sgoutham@xxxxxxxxxxx>; Linu Cherian <lcherian@xxxxxxxxxxx>;
> Geethasowjanya Akula <gakula@xxxxxxxxxxx>; Jerin Jacob Kollanukkaran
> <jerinj@xxxxxxxxxxx>; Subbaraya Sundeep Bhatta <sbhatta@xxxxxxxxxxx>;
> Felix Manlunas <fmanlunas@xxxxxxxxxxx>; Christina Jacob
> <cjacob@xxxxxxxxxxx>; Sunil Kovvuri Goutham
> <Sunil.Goutham@xxxxxxxxxx>
> Subject: [EXT] Re: [Patch v2 net-next 2/7] octeontx2-af: Add new CGX_CMD
> to get PHY FEC statistics
> On Sat, Jan 30, 2021 at 4:53 AM Hariprasad Kelam <hkelam@xxxxxxxxxxx>
> wrote:
> >
> > Hi Willem,
> >
> > > -----Original Message-----
> > > From: Willem de Bruijn <willemdebruijn.kernel@xxxxxxxxx>
> > > Sent: Thursday, January 28, 2021 1:50 AM
> > > To: Hariprasad Kelam <hkelam@xxxxxxxxxxx>
> > > Cc: Network Development <netdev@xxxxxxxxxxxxxxx>; LKML <linux-
> > > kernel@xxxxxxxxxxxxxxx>; David Miller <davem@xxxxxxxxxxxxx>; Jakub
> > > Kicinski <kuba@xxxxxxxxxx>; Sunil Kovvuri Goutham
> > > <sgoutham@xxxxxxxxxxx>; Linu Cherian <lcherian@xxxxxxxxxxx>;
> > > Geethasowjanya Akula <gakula@xxxxxxxxxxx>; Jerin Jacob Kollanukkaran
> > > <jerinj@xxxxxxxxxxx>; Subbaraya Sundeep Bhatta
> > > <sbhatta@xxxxxxxxxxx>; Felix Manlunas <fmanlunas@xxxxxxxxxxx>;
> > > Christina Jacob <cjacob@xxxxxxxxxxx>; Sunil Kovvuri Goutham
> > > <Sunil.Goutham@xxxxxxxxxx>
> > > Subject: [EXT] Re: [Patch v2 net-next 2/7] octeontx2-af: Add new
> > > CGX_CMD to get PHY FEC statistics
> > >
> > > On Wed, Jan 27, 2021 at 4:04 AM Hariprasad Kelam
> > > <hkelam@xxxxxxxxxxx>
> > > wrote:
> > > >
> > > > From: Felix Manlunas <fmanlunas@xxxxxxxxxxx>
> > > >
> > > > This patch adds support to fetch fec stats from PHY. The stats are
> > > > put in the shared data struct fwdata.  A PHY driver indicates that
> > > > it has FEC stats by setting the flag fwdata.phy.misc.has_fec_stats
> > > >
> > > > Besides CGX_CMD_GET_PHY_FEC_STATS, also add CGX_CMD_PRBS and
> > > > CGX_CMD_DISPLAY_EYE to enum cgx_cmd_id so that Linux's enum list
> > > > is in sync with firmware's enum list.
> > > >
> > > > Signed-off-by: Felix Manlunas <fmanlunas@xxxxxxxxxxx>
> > > > Signed-off-by: Christina Jacob <cjacob@xxxxxxxxxxx>
> > > > Signed-off-by: Sunil Kovvuri Goutham <Sunil.Goutham@xxxxxxxxxx>
> > > > Signed-off-by: Hariprasad Kelam <hkelam@xxxxxxxxxxx>
> > >
> > >
> > > > +struct phy_s {
> > > > +       struct {
> > > > +               u64 can_change_mod_type : 1;
> > > > +               u64 mod_type            : 1;
> > > > +               u64 has_fec_stats       : 1;
> > >
> > > this style is not customary
> >
> > These structures are shared with firmware and stored in a shared memory.
> Any change in size of structures will break compatibility. To avoid frequent
> compatible issues with new vs old firmware we have put spaces where ever
> we see that there could be more fields added in future.
> > So changing this to u8 can have an impact in future.
> 
> My comment was intended much simpler: don't add whitespace between the
> bit-field variable name and its size expression.
> 
>   u64 mod_type:1;
> 
> not
> 
>   u64 mod_type     : 1;
> 
> At least, I have not seen that style anywhere else in the kernel.
Got it . Will fix this in next version.

Thanks,
Hariprasad k