Re: [dpdk-dev] [PATCH v7 3/6] igb_uio: fix MSI-X IRQ assignment with new IRQ function

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 9/5/2017 1:04 PM, Markus Theil wrote:
> The patch which introduced the usage of pci_alloc_irq_vectors
> came after the patch which switched to non-threaded ISR (f0d1896fa1),
> but did not use non-threaded ISR, if pci_alloc_irq_vectors
> is used.
> 
> Fixes: 99bb58f3adc7 ("igb_uio: switch to new irq function for
> MSI-X")
> Cc: nicolas.dichtel@6wind.com
> 
> Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
> ---
>  lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> index 93bb71d..6885e72 100644
> --- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> +++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> @@ -331,6 +331,7 @@ igbuio_pci_enable_interrupts(struct rte_uio_pci_dev *udev)
>  #else
>  		if (pci_alloc_irq_vectors(udev->pdev, 1, 1, PCI_IRQ_MSIX) == 1) {
>  			dev_dbg(&udev->pdev->dev, "using MSI-X");
> +			udev->info.irq_flags = IRQF_NO_THREAD;

IRQF_NO_THREAD seems has been introduced in 2.6.39, so using this flag
causing build error for kernel versions < 2.6.39.

btw, the flag is already in use, so issue is not related to this patch.

In DPDK documentation supported Linux kernel version is >= 2.6.34 [1].

We should either increase supported version to 2.6.39, or update igb_uio
code.

I am for increasing minimum supported kernel version to 2.6.39, any
objection / comment?

2.6.39 released on May 2011
2.6.34 released on May 2010


[1]
http://dpdk.org/doc/guides/linux_gsg/sys_reqs.html#system-software

>  			udev->info.irq = pci_irq_vector(udev->pdev, 0);
>  			udev->mode = RTE_INTR_MODE_MSIX;
>  			break;
>