On Thu, Jun 2, 2016 at 11:59 PM, Luca Coelho [off-list ref] wrote:

On Thu, 2016-06-02 at 23:09 -0600, Reinoud Koornstra wrote:

quoted

On Thu, Jun 2, 2016 at 2:16 AM, Luca Coelho [off-list ref] wrote:

quoted

This shows that you have iwlwifi-7260-16.ucode in your file system.
 But here we are reading it much later.  So it's possible that the
kernel cannot access the firmware at a very early stage (because
the
filesystem that contains it is not mounted yet) when you use in-
kernel.

So, first of all, please make sure they're built as modules.  We
can
continue from there then.

Your suggestion worked. When it's compiled as module, the
iwlwifi-7260-16.ucode loads fine.
No problems detected so far.

Great! :)

It is. :)
I git pulled again and build it again.
This time with gcc 6.1.0
I couldn't find warning specific to iwlwifi with gcc 6, so that's great.
Didn't find anything worrysome yet, in addition I am running the cake
qdisc as well from Dave Taht.
objdump --full-contents --section=.comment vmlinux

vmlinux:     file format elf64-x86-64

Contents of section .comment:
0000 4743433a 2028474e 55292036 2e312e30  GCC: (GNU) 6.1.0
0010 00

reinoud@router-dev:~/Downloads/wireless-testing$ objdump
--full-contents --section=.comment
/lib/modules/4.7.0-rc1-wt+/kernel/drivers/net/wireless/intel/iwlwifi/iwlwifi.ko

/lib/modules/4.7.0-rc1-wt+/kernel/drivers/net/wireless/intel/iwlwifi/iwlwifi.ko:
    file format elf64-x86-64

Contents of section .comment:
0000 00474343 3a202847 4e552920 362e312e  .GCC: (GNU) 6.1.
0010 30000047 43433a20 28474e55 2920362e  0..GCC: (GNU) 6.
[SNIP]
0180 28474e55 2920362e 312e3000           (GNU) 6.1.0.

quoted

It does make me think whether this is desired behavior though that
due
to the later reading we cannot have iwlwifi build in the kernel.

It should work, but then you have to make sure the firmware is
available at very early stages of boot.  If you add it to the proper
place in your initrd, the kernel should find it when the driver
requests it.

I didn't want to go into the details of this, because in most cases the
best option is to have the driver as a module.  If you really need it
in-kernel, then you need to make sure all the needed pieces are
available very early as well.

Ah, thanks, I'll study this as how to have it inside initrd at the right place.
Any pointers would be great.

Btw, I did build gcc 6.1.0 like this, if you have hints or ways I
should build it differently I would like to know.

reinoud@router-dev:~/Downloads/wireless-testing$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/home/reinoud/GCC/libexec/gcc/x86_64-linux-gnu/6.1.0/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../gcc-6.1.0/configure -v
--enable-languages=c,c++,go,fortran,objc,obj-c++
--prefix=/home/reinoud/GCC --enable-shared --enable-linker-build-id
--without-included-gettext --enable-threads=posix --enable-nls
--with-sysroot=/ --enab
le-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-libmpx --enable-plugin
--with-system-zlib --disable-browser-plugin --with-arch-direct
ory=amd64 --enable-objc-gc --enable-multiarch --disable-werror
--with-abi=m64 --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 6.1.0 (GCC)

The --with-tune=skylake didn't work as it didn't know it. unfortunately.

--
Cheers,
Luca.

Thanks,

Reinoud.