The module parameter is read-only since changing mode after loading isn't going to work.
Signed-off-by: Stephen Hemminger <stephen at networkplumber.org> --- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c 2014-07-18 08:42:54.028654483 -0700 +++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c 2014-07-18 08:42:54.028654483 -0700 @@ -721,7 +721,7 @@ igbuio_pci_exit_module(void) module_init(igbuio_pci_init_module); module_exit(igbuio_pci_exit_module); -module_param(intr_mode, charp, S_IRUGO | S_IWUSR); +module_param(intr_mode, charp, S_IRUGO); MODULE_PARM_DESC(intr_mode, "igb_uio interrupt mode (default=msix):\n" " " RTE_INTR_MODE_MSIX_NAME " Use MSIX interrupt\n"