Bug#908632: linux-image-4.19.0-rc3-amd64-unsigned: kernel 4.19 fails to load amdgpu driver on R9 270X.

[Romain Perier <romain.perier@gmail.com>]

Hello,


On Fri, Sep 21, 2018 at 02:13:27PM -0300, felipe wrote:
> Tested again with experimental kernel 4.19-rc4 and the result is the same (not able to find firmware) as with 4.19-rc3
> and 4.19-rc2.
> 
> Tried reinstalling the firmware-amd-graphics and firmware-linux packages.
> 
> Booting with kernel parameters 'radeon.si_support=0 amdgpu.si_support=1' and kernel 4.19.rc-4 the system bails and
> cannot find the required firmware which is located at '/lib/firmware/radeon'.
> 
> If I copy the contents of '/lib/firmware/radeon' to '/lib/firmware/amdgpu' and restart, the system boots, loads the
> firmware and works.
> 
> Since previous kernels (4.17, 4.18) the system had no problem finding the correct firmware inside '/lib/firmware/radeon'
> when using amdgpu driver.
>

Yeah that's introduced by commit https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8eaf2b1faaf4358c6337785f2192055c6ef41e0d

Instead of copying all the content of /lib/firmware/radeon into
/lib/firmware/amdgpu, could you:

1. Uninstall firmware-amd-graphics properly so /lib/firmware/radeon and
/lib/firmware/amdgpu are empty
2. Re-install firmware-amd-graphics properly from archives (so,
basically, these two steps undo your changes)
3. Copy only /lib/firmware/radeon/pitcairn_mc.bin to
/lib/firmware/amdgpu/pitcairn_mc.bin

Does this work for you ? Otherwise try to find messages in dmesg
complaining about missing firmware for your amdgpu driver, then
copy the right missing firmwares from /lib/firmware/radeon to
/lib/firmware/amdgpu and then once it works, please paste a list here.

Thanks in advance,
Regards,
Romain

> 
> 
> 
> On 9/13/18 1:44 PM, felipe wrote:
> > Today I had some spare time and I did some tests.
> > 
> > On kernel 4.17 and 4.18 I can switch from radeonsi to amdgpu using/removing 'radeon.si_support=0 amdgpu.si_support=1'
> > and the system finds and loads the relevant firmware in /lib/firmware/radeon, giving this system a boost in performance,
> > correct HDMI output and no crashes.
> > 
> > Booting kernel 4.19, the system could not load the relevant firmware when I tried to use amdgpu, but booted using radeonsi.
> > 
> > Today I did copy all the firmware in '/lib/firmware/radeon' to '/lib/firmware/amdgpu' and the system booted in a working
> > state and has been stable for the last hour.
> > 
> > Since it is possible to use amdgpu with older GCN cards, the kernel should also look for the firmware inside
> > '/lib/firmware/radeon' when using 'amdgpu' driver.
> > 
> > 
> > '$ cat /var/log/syslog' of this working session with kernel 4.19-rc3 and 'cp /lib/firmware/radeon/* /lib/firmware/amdgpu'