From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Date: Wed, 29 Jun 2016 13:32:42 -0700 Subject: [Intel-wired-lan] Question on i40e PCIe relaxed ordering (RO) In-Reply-To: <1467231519.3404.11.camel@gmail.com> References: <57742A27.5040207@oracle.com> <1467231519.3404.11.camel@gmail.com> Message-ID: <1467232362.3733.23.camel@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: On Wed, 2016-06-29 at 13:18 -0700, Greg wrote: > On Wed, 2016-06-29 at 13:05 -0700, tndave wrote: > > Hi, > >? > > Running iperf tcp test on 2 sparc systems with i40e connected back to > > back, I see huge number of 'port.rx_dropped' (on iperf server). Based > on > > past experience with ixgbe, this could very well because of PCIe RO > > (relaxed ordering) not enabled. > >? > > I am trying to confirm RO is enabled. i40e datasheet mentioned RO > > settings in 3 different sections: > >? > > 1. section 10.2.2.2.38 PCIe Global Config 2 - GLPCI_CNF2 register > > contains global status fields of PCIe configuration. The bit 0 of the > > register is "RO_DIS". If this bit is set to 1 RO is disabled. > >? > > RO_DIS in my setup is 0 imply RO is not disabled. > >? > > 2. section 12.3.5.5 Device Control Register (0xA8; RW) has bit 4 > > that enable/disable RO. This is pcie cap register. > >? > > In my i40e pcie config space value at offset 0xA8 is "2110". i.e 4th > bit > > set to 1 imply RO is enabled. > >? > > 3. section 3.1.2.7.2 mentions some relaxed ordering rules > > e.g. "The GLLAN_RCTL.RXDESCRDROEN bit (loaded from NVM) enables relaxed > > ordering for Rx descriptor reads" > >? > > However, GLLAN_RCTL register definition has not bit like RXDESCRDROEN. > > Same goes for GLLAN_TCTL.TXDESCRDROEN. > >? > > Am I missing anything? please advise. > > I would try posting this question to the e1000 developer list over at > Source Forge.? The Intel customer support folks used to monitor that > list closely when I was there, hopefully they still are. We are supposed to be monitoring both lists, but just in case I have added e1000-devel list... -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: This is a digitally signed message part URL: