When insmod "igb_uio" with "intr_mode=legacy and test link status interrupt. Since INTx interrupt is not supported by X710/XL710/XXV710, it will cause Input/Output error when reading file descriptor.
Signed-off-by: Qiming Yang <qiming.y...@intel.com> --- doc/guides/nics/i40e.rst | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/doc/guides/nics/i40e.rst b/doc/guides/nics/i40e.rst index 043de34..f4073c2 100644 --- a/doc/guides/nics/i40e.rst +++ b/doc/guides/nics/i40e.rst @@ -467,3 +467,16 @@ Incorrect Rx statistics when packet is oversize When a packet is over maximum frame size, the packet is dropped. However the Rx statistics, when calling `rte_eth_stats_get` incorrectly shows it as received. + +igb uio legacy mode can not be used in X710/XL710/XXV710 +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +When insmod ``igb_uio`` with ``intr_mode=legacy`` and test link status +interrupt, it will cause Input/Output error when reading file descriptor. +The root cause is X710/XL710/XXV710 NICs lack support for indicating INTx +is asserted via the interrupt bit in the PCI status register. Linux delect +them from INTx support table. The related link `linux kernel commit <https: +//git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/ +drivers/pci/quirks.c?id=8bcf4525c5d43306c5fd07e132bc8650e3491aec>`_. + +NOTE: happening when Linux kernel version >= 4.7 -- 2.7.4
