Messages in this thread | | | From | Vladimir Oltean <> | Date | Thu, 30 May 2019 10:42:41 +0300 | Subject | Re: [PATCH net-next 3/5] net: dsa: mv88e6xxx: Let taggers specify a can_timestamp function |
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On Thu, 30 May 2019 at 06:51, Richard Cochran <richardcochran@gmail.com> wrote: > > On Wed, May 29, 2019 at 11:33:31PM +0300, Vladimir Oltean wrote: > > I would like to avoid keeping meta frames in their own RX queue, > > because then I'm complicating (or rather put, making impossible) the > > association between a meta frame and the frame it holds a timestamp > > of. > > We have an example of how a driver can match meta time stamp packets > with received packets. See drivers/net/phy/dp83640.c to see how it > can be done completely within the driver. > > Thanks, > Richard
The meta frames generated by the SJA1105 do not contain any seqid. They contain: * A globally programmable DMAC * A globally programmable SMAC * The 0x8 EtherType * A partial (24-bit or 32-bit) RX timestamp * Two bytes from the initial (pre follow-up) frame's DMAC, before the switch mangled those with the source port and switch id. The driver is supposed to patch these bytes from the follow-up back into the initial frame before passing them up the stack. * The source port that generated the meta frame * The switch id that generated the meta frame
Regards, -Vladimir
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