From mboxrd@z Thu Jan  1 00:00:00 1970
From: Patrick MacArthur <patrick@patrickmacarthur.net>
Subject: Re: [PATCH] igb_uio: fix unknown symbols
Date: Thu, 12 Oct 2017 23:21:08 -0400
Message-ID: <7673fa98-986e-abde-a68c-01809d01caec@patrickmacarthur.net>
References: <20171013024644.51248-1-ferruh.yigit@intel.com>
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Cc: dev@dpdk.org, mark.b.kavanagh@intel.com, stephen@networkplumber.org,
 markus.theil@tu-ilmenau.de, Patrick MacArthur <pmacarth@iol.unh.edu>,
 Bob Noseworthy <ren@iol.unh.edu>, "O'Driscoll, Tim" <tim.odriscoll@intel.com>
To: Ferruh Yigit <ferruh.yigit@intel.com>
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On 10/12/2017 10:46 PM, Ferruh Yigit wrote:
> This patch partially reverts the commit d196343a258e and adds some
> functions from Markus' previous version of the patch [1].
> 
> igb_uio uses pci_msi_unmask_irq() and pci_msi_mask_irq() kernel APIs
> when kernel version is >= 3.19 because these APIs are implemented in
> this Linux kernel version.
> 
> But these APIs only exported beginning from Linux kernel 4.5, so before
> this Linux kernel version igb_uio kernel module is not usable,
> and giving following warnings:
> "igb_uio: Unknown symbol pci_msi_unmask_irq"
> "igb_uio: Unknown symbol pci_msi_mask_irq"
> 
> The support for these APIs increased to Linux kernel >= 4.5
> 
> For older version of Linux kernel unmask_msi_irq() and mask_msi_irq()
> are used but these functions are not exported at all.
> Instead of these functions switched back to previous implementation in
> igb_uio for MSI-X, and for MSI used igbuio_msi_mask_irq() from [1].
> 
> Fixes: d196343a258e ("igb_uio: use kernel functions for masking MSI-X")
> Cc: markus.theil@tu-ilmenau.de
> 
> [1]
> http://dpdk.org/dev/patchwork/patch/28144/
> 
> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>

I can confirm that with this patch applied I am able to build and load 
the igb_uio module on CentOS 7.4. I have not tested the actual MSI-X 
interrupt mask/unmask functionality.