Hi:
If INTX fails, igb_uio falls back to running without IRQ ( refer to the
implementation in igbuio_pci_probe).
On QEMU 0.12.0, the INTX seems to have broken, and the intr_mode falls to
RTE_INTR_MODE_NONE
However this sets the udev->info.irq = 0;
Setting of udev->info.irq to ?0? does not work on *2.6.36 and lower
kernels*, because the UIO_IRQ_NONE is defined as
#define UIO_IRQ_NONE -2
Because the udev->info.irq is set to ?0?, on *2.6.36 and below*
implementation, the *__uio_register_device* invokes request_irq
if (idev->info->irq >= 0) {
ret = request_irq(idev->info->irq, uio_interrupt,
and it fails with the following dump
IRQ handler type mismatch for IRQ 0
current handler: timer
Pid: 3106, comm: dpdk_nic_bind.p Not tainted 2.6.32-504.23.4.el6.x86_64 #1
Call Trace:
[<ffffffff810ebd62>] ? __setup_irq+0x382/0x3c0
[<ffffffffa033f2a0>] ? uio_interrupt+0x0/0x48 [uio]
[<ffffffff810ec563>] ? request_threaded_irq+0x133/0x230
[<ffffffffa033f193>] ? __uio_register_device+0x553/0x610 [uio]
[<ffffffffa0345652>] ? igbuio_pci_probe+0x3a7/0x4a0 [igb_uio]
[<ffffffff8128e58a>] ? kobject_get+0x1a/0x30
[<ffffffff812af417>] ? local_pci_probe+0x17/0x20
[<ffffffff812b0601>] ? pci_device_probe+0x101/0x120
[<ffffffff8136c992>] ? driver_sysfs_add+0x62/0x90
[<ffffffff8136cc2c>] ? driver_probe_device+0x9c/0x3e0
[<ffffffff8136bd6a>] ? driver_bind+0xca/0x110
[<ffffffff8136ae3c>] ? drv_attr_store+0x2c/0x30
[<ffffffff8120a4c5>] ? sysfs_write_file+0xe5/0x170
[<ffffffff8118e1c8>] ? vfs_write+0xb8/0x1a0
[<ffffffff8118eb91>] ? sys_write+0x51/0x90
[<ffffffff8100b0f2>] ? system_call_fastpath+0x16/0x1b
igb_uio 0000:00:03.0: PCI INT A disabled
igb_uio: probe of 0000:00:03.0 failed with error -16
On kernel *2.6.37* and above, the definition is,
#define UIO_IRQ_NONE 0
And the check is,
if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
ret = request_irq(info->irq, uio_interrupt,
info->irq_flags, info->name, idev);
So to handle the ?RTE_INTR_MODE_NONE? in these different kernel versions,
We are proposing the following change to the code in igbuio_pci_probe
function,
case RTE_INTR_MODE_NONE:
udev->mode = RTE_INTR_MODE_NONE;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 37)
udev->info.irq = -2;
#else
udev->info.irq = 0;
#endif
Please let me know your opinion. If it is correct, we will go ahead and
generate a patch for review.
Regards,
Prathap
