Re: [dpdk-dev] [PATCH] igb_uio: MSI IRQ mode, irq enable/disable refactored

[Markus Theil <markus.theil@tu-ilmenau.de>]

On 22.08.2017 18:55, Stephen Hemminger wrote:
> On Mon, 21 Aug 2017 19:33:45 +0200
> Markus Theil <markus.theil@tu-ilmenau.de> wrote:
>
>> This patch adds MSI IRQ mode and in a way, that should
>> also work on older kernel versions. The base for my patch
>> was an attempt to do this in cf705bc36c which was later reverted in
>> d8ee82745a. Compilation was tested on Linux 3.2, 4.10 and 4.12.
>>
>> MSI(X) setup was already using pci_alloc_irq_vectors before,
>> but calls to pci_free_irq_vectors were missing and added.
>>
>> Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
> I wonder if DPDK should only N-1 Long Term Stable kernel.org kernels?
> That would mean 4.4.83 or later now, and 4.9 or later starting with 18.XX releases.
>
> If enterprise distro's want to backport more, that is their prerogative but upstream
> DPDK shouldn't have to worry about it. The current mess with KNI especially is out
> of hand.
I don't rely on older kernels than N-1 LTS, but the former MSI patch was
reverted
because of such an issue. If there is consensus about this, adapting
igb_uio
to kernels >= 4.4 will be no problem. I'd then write a little patch
series with that aim.