On Thu, Sep 19, 2019 at 10:00:51AM +0200, Sascha Hauer wrote: > Hi Vladimir, > > On Wed, Sep 18, 2019 at 05:36:08PM +0300, Vladimir Oltean wrote: > > Hi Sascha, > > > > On Wed, 18 Sep 2019 at 17:03, Sascha Hauer <s.ha...@pengutronix.de> wrote: > > > > > > Hi All, > > > > > > We have a customer using a Marvell 88e6240 switch with Ethercat on one > > > port and > > > regular network traffic on another port. The customer wants to configure > > > two things > > > on the switch: First Ethercat traffic shall be priorized over other > > > network traffic > > > (effectively prioritizing traffic based on port). Second the ethernet > > > controller > > > in the CPU is not able to handle full bandwidth traffic, so the traffic > > > to the CPU > > > port shall be rate limited. > > > > > > > You probably already know this, but egress shaping will not drop > > frames, just let them accumulate in the egress queue until something > > else happens (e.g. queue occupancy threshold triggers pause frames, or > > tail dropping is enabled, etc). Is this what you want? > > If I understand correctly then the switch has multiple output queues per > port. The Ethercat traffic will go to a higher priority queue and on > congestion on other queues, frames designated for that queue will be > dropped. I just talked to our customer and he verified that their > Ethercat traffic still goes through even when the ports with the general > traffic are jammed with packets. So yes, I think this is what I want.
Moreover egressing the cpu port has the advantage that network participants on other ports that might be able to process packet quicker are not limited. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |
