On Fri, 1 Aug 2025 17:10:44 +0400 (+04) Ivan Malov <ivan.ma...@arknetworks.am> wrote:
> Hi Renata, > > On Fri, 1 Aug 2025, Renata Saiakhova wrote: > > > > > Hi all, > > > > I’m trying to configure Layer 1 attributes (speed, duplex, and > > autonegotiation) for Intel i225 interfaces in both kernel and DPDK modes, > > and I’ve run into some issues. > > > > In kernel driver mode, I normally use: “ethtool -s eth5 speed 100 duplex > > half autoneg off”. > > > > However, this results in the kernel message: “igc 0000:04:00.0 eth5: Force > > mode currently not supported”. > > > > > > > > When the interface is bound to DPDK and connected to an OVS bridge, I > > configure it like this: > > > > ovs-vsctl set Interface 1.extra2 \ > > > > type=dpdk \ > > > > options:dpdk-devargs=0000:04:00.0 \ > > > > options:dpdk-speed=100 \ > > > > options:dpdk-autoneg=false \ > > > > options:dpdk-duplex=half > > > > This should pass the speed/autoneg/duplex settings to the igc DPDK driver > > via devargs. > > Should it? Even if these were on the list of supported devargs for the PMD in > question, they would belong in comma-separated tokens after '0000:04:00.0'. > I don't see these to be parsed in the OvS, neither do I see such in the PMD. > > Or are you looking at some custom OvS version? > > > > > However, it appears these options are not applied — the interface continues > > to negotiate its settings as usual, and I can’t find any code in the igc > > DPDK driver that processes these > > devargs parameters. > > If these were passed via 'dpdk-devargs', the PMD would've complained perhaps. > Being passed as OvS's own options, they're likely just ignored by the OvS. > > > > > Is support for forced speed/duplex/autoneg available at all for i225 in > > DPDK (or even kernel) mode? Or is this a hardware limitation? > > As per [1], 'forced' mode may not be supported in the DPDK PMD. But the code > suggests one can possibly try to pass, say, 'RTE_ETH_LINK_SPEED_100M_HD', > without being accompanied by neither 'AUTONEG' nor 'FIXED', but that would > still > come as 'advertised' mode, not a 'forced' one. I may be wrong, though. > > [1] > https://github.com/DPDK/dpdk/blob/1b3bf1128d9bda5595861814792f74b8f57160c8/drivers/net/igc/igc_ethdev.c#L1088 > > > > > Any insight, documentation pointers, or confirmation of support status > > especially in case of DPDK mode would be greatly appreciated. > > I take it OvS most likely needs to be augmented with extra code to recognise > such options and translate those into DPDK link settings. For an example of > how > a DPDK application can do that, one should refer to 'test-pmd' implementation. > > Thank you. > > > > > Best regards, > > > > > > > > > > > > Renata Saiakhova > > SW ARCHITECT > > renata.saiakh...@ekinops.com > > Tel: +32 16 799 970 > > > > [logo_96dpi.gif] > > > > [current.png] > > > > > > > > > > Use of driver specific devargs is strongly discouraged. There is link_speeds in rte_eth_conf passed to rte_eth_dev_configure() which is the correct way to set fixed speed. It maybe that the driver doesn't interpret it correctly?
