Re: "swiotlb buffer is full" problem with tg3 and kernel 3.16.0-4-686-pae on Xen 4.4.1

[Marco Steinacher <mailinglists@websource.ch>]

Am 21.05.2015 um 20:11 schrieb Ian Campbell:
> On Thu, 2015-05-21 at 17:17 +0200, Marco Steinacher wrote:
>> Shall I try to build a 3.16.0-4-686-pae kernel with
>> "CONFIG_NEED_DMA_MAP_STATE=y"?
> 
> Yes, this is what I would recommend. Although it's not as simple as
> turning it on, you actually need to patch the Kconfig as in this mail:
> http://www.spinics.net/lists/netdev/msg325844.html such that it comes on
> by itself.

Thanks for pointing me in the right direction. I compiled a custom
kernel following [0] and the following change:

--- linux-source-3.16.orig/arch/x86/Kconfig     2015-04-24
04:05:11.000000000 +0200
+++ linux-source-3.16/arch/x86/Kconfig  2015-05-22 06:14:17.393963697 +0200
@@ -164,7 +164,7 @@

 config NEED_DMA_MAP_STATE
        def_bool y
-       depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
+       depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB

 config NEED_SG_DMA_LENGTH
        def_bool y

And this solved the problem for me. No "swiotlb buffer is full" messages
anymore and the network interface works just fine again.

> If you could file your results into the Debian BTW, i.e. by running
> "reportbug <linux-image-pkg-name>" then that would be useful to help get
> it fixed in a future update.

Done [1].

Thanks a lot,
Marco

[0] https://www.debian.org/releases/jessie/i386/ch08s06.html.en
[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=786551

-- 
OpenPGP Key ID: 0x62937F7F