RE: [PATCH net-next v8 2/2] net: ti: icssg_prueth: add TAPRIO offload support

[Keller, Jacob E]

> -----Original Message-----
> From: Anwar, Md Danish <a0501179@xxxxxx>
> Sent: Thursday, May 30, 2024 9:25 PM
> To: Keller, Jacob E <jacob.e.keller@xxxxxxxxx>; MD Danish Anwar
> <danishanwar@xxxxxx>; Kiszka, Jan <jan.kiszka@xxxxxxxxxxx>; Dan Carpenter
> <dan.carpenter@xxxxxxxxxx>; Andrew Lunn <andrew@xxxxxxx>; Simon Horman
> <horms@xxxxxxxxxx>; Diogo Ivo <diogo.ivo@xxxxxxxxxxx>; Wolfram Sang
> <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>; Randy Dunlap
> <rdunlap@xxxxxxxxxxxxx>; Niklas Schnelle <schnelle@xxxxxxxxxxxxx>; Vladimir
> Oltean <vladimir.oltean@xxxxxxx>; Vignesh Raghavendra <vigneshr@xxxxxx>;
> Richard Cochran <richardcochran@xxxxxxxxx>; Roger Quadros
> <rogerq@xxxxxxxxxx>; Paolo Abeni <pabeni@xxxxxxxxxx>; Jakub Kicinski
> <kuba@xxxxxxxxxx>; Eric Dumazet <edumazet@xxxxxxxxxx>; David S. Miller
> <davem@xxxxxxxxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; srk@xxxxxx; Roger Quadros <rogerq@xxxxxx>
> Subject: Re: [PATCH net-next v8 2/2] net: ti: icssg_prueth: add TAPRIO offload
> support
> 
> Hi Jacob,
> 
> On 5/30/2024 11:45 PM, Jacob Keller wrote:
> >
> >
> > On 5/29/2024 4:05 AM, MD Danish Anwar wrote:
> >> From: Roger Quadros <rogerq@xxxxxx>
> >>
> >> The ICSSG dual-emac / switch firmware supports Enhanced Scheduled Traffic
> >> (EST – defined in P802.1Qbv/D2.2 that later got included in IEEE
> >> 802.1Q-2018) configuration. EST allows express queue traffic to be
> >> scheduled (placed) on the wire at specific repeatable time intervals. In
> >> Linux kernel, EST configuration is done through tc command and the taprio
> >> scheduler in the net core implements a software only scheduler
> >> (SCH_TAPRIO). If the NIC is capable of EST configuration,user indicate
> >> "flag 2" in the command which is then parsed by taprio scheduler in net
> >> core and indicate that the command is to be offloaded to h/w. taprio then
> >> offloads the command to the driver by calling ndo_setup_tc() ndo ops. This
> >> patch implements ndo_setup_tc() to offload EST configuration to ICSSG.
> >>
> >> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
> >> Signed-off-by: Vignesh Raghavendra <vigneshr@xxxxxx>
> >> Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
> >> Signed-off-by: MD Danish Anwar <danishanwar@xxxxxx>
> >> ---
> >
> > I tried to apply this series to review it. Unfortunately It no longer
> > applies cleanly since it has textual conflicts with 972383aecf43 ("net:
> > ti: icssg-switch: Add switchdev based driver for ethernet switch
> > support"), which was part of:
> >
> > https://lore.kernel.org/netdev/20240528113734.379422-1-
> danishanwar@xxxxxx/
> >
> > The conflict seemed easy enough to resolve, but I'm not sure if the
> > prueth_qos structure would be placed optimally. I tried to build the
> > driver to check what the placement should be and was unable to get
> > things to compile.
> 
> When I had posted this series (v8) the ICSSG switch series was not
> merged yet and I had rebased this series on net-next/main. When you
> tested it, the ICSSG Series was merged and as it resulted in conflict.
> 
> I will rebase it on the latest net-next and make sure that their is no
> conflict and post next revision.
> 
> Thanks for your feedback.
> 
> --
> Thanks and Regards,
> Md Danish Anwar

I assumed as much 😊 I just wanted to point out that the conflict is non-trivial because its hard to tell whether the new structure would fit best before or after the other data added by the switch series, or if it would be even better to arrange it somewhere else in the structure entirely.

Thanks,
Jake