On Tue, Mar 30, 2021 at 11:40:42AM -0700, Jacob Keller wrote: > On 3/22/2021 8:40 AM, Miroslav Lichvar wrote: > > FWIW, some onboard NICs supported by the e1000e driver can > > "cross-timestamp" using the Always Running Timer (ART), which should > > avoid the asymmetry of PCIe. I have not seen any detailed description > > of how it actually works. > > > > I'm not sure in the e1000e case but in general this is done via PCIe > Precision Time Measurement extension which allows an end-point device > that supports the function to setup a transaction that captures the > device clock and ART value near-simultaneously. > > I think the e1000e support might be a variation of this which pre-dated > the PTM standard and works when the device is a LAN-on-motherboard.
My understanding was that the e1000e did in fact implement the newfangled PCIe thingy. But I could be wrong. Thanks, Richard _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
