On Thu, Oct 04, 2018 at 03:38:41PM +0000, Keller, Jacob E wrote: > > On Wed, Oct 03, 2018 at 09:39:14PM +0000, Keller, Jacob E wrote: > > > I'm investigating a potential software driver bug in which a driver calls > > skb_tx_timestamp earlier than necessary, and I want to gather some > > informational > > data to indicate whether or not moving the function to a later point in the > > driver tx/rx > > path would actually improve the accuracy/precision. > > > > You mean the TX path only? An RX timestamp should be captured as soon > > as possible. > > > > This is Tx path, because that's the bit controlled by the drivers. AFAIK the > Rx timestamping is done by the stack when the driver pushes the SKB up, right?
Yes, I think that's how it's supposed to work, but I'm not sure if a driver couldn't put there a more accurate timestamp earlier. Ideally, the RX timestamp would be taken right after the interrupt (if there was one), like with PPS for instance. -- Miroslav Lichvar _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
