> On Tue, Feb 17, 2015 at 5:31: PM +0100, Richard Cochran wrote: <snip>
> This is done differently in every driver, depending on the hardware. > > Some hardware provides the time stamp "in band", for example in the > frame's buffer descriptor or in the frame data. In this case, the > association is clear. > > Other (worse) hardware provides the time stamp "out of band", separate > from the frame, in a time stamp fifo for example. Sometimes there is > no fifo but rather a single register! In these cases, the driver must > somehow match the time stamp with a frame. Some hardware provides > various matching fields with the time stamp, like sequence number, > message type, or a hash over multiple fields. It all depends on the > hardware. If you look into various drivers, you will find functions > called match(). There you can see exactly what fields are used. > > HTH > Richard That helps a lot. Thank you very much! I came across Windows implementations where only the sequence id is used and IMHO this is not sufficient (thinking of different domains on the same network). Cheers Axel ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=190641631&iu=/4140/ostg.clktrk _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
