On 1/24/2017 19:25, Juergen Stuber wrote: > Hi, > > I'm trying to get hardware timestamps for received packets on a 82579LM (PCI > id 8086:1502). > I do get timestamps, but the time advances by a factor of 3.84 too fast. > In the datasheet on page 132 it says "The clock used has stable 96MHz or > 25Mhz frequency", > but not which (there is no other mention of these frequencies in the data > sheet). > The driver reads bit 5 of TSYNCRXCTL, which is reserved for 82579, but > documented as SYSCFI for i217, > with 0: 25MHz and 1: 96MHz. > The Linux driver e1000e decides based on this flag between 25 and 96 MHz, > apparently it wrongly chooses 25MHz > instead of 96MHz in my case (netdev.c, e1000e_get_base_timinca(), case > e1000_pch2lan). > > I see that the clock is enabled before reading the flag for i217 and similar, > but not for 82579, could that be a factor? > If yes, how should it be fixed? > > I’m using Linux 4.4, but I don't see any significant differences to 4.9 in > this code. > > Regards > Jürgen > > -- > Jürgen Stuber > > Software Developer > Core Real Time Implementation > > dSPACE GmbH, Rathenaustr. 26, 33102 Paderborn, Germany > http://www.dspace.de > mailto:jstuber.h...@dspace.de > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > E1000-devel mailing list > E1000-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/e1000-devel > To learn more about Intel® Ethernet, visit > http://communities.intel.com/community/wired
Hello Jürgen, For e1000_pch2lan and e1000_pch_lpt implemented 96MHz and 25MHz frequency. What is value you read from TSYNCRXCTL.SYSCFI (bit 5)? Please, try change your code locally that allow you select 96MHz even when bit 5 is zero. Will this help you? What is platform you use? Describe scenario that you run, step by step. 82579LM and i217 are different devices. Anyway, I recommended use last published on source Forge e1000e-3.3.5.3 version of driver. Also, please, fill bug ticket on https://sourceforge.net/p/e1000/bugs/ Thanks, Sasha ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
