NAK: [PATCH 0/1][SRU][Focal] Workaround for FLR bug in AMD Startship/Matisse USB and HD audio controllers

[Kleber Souza]

On 2020-05-24 17:47, Marcos Scriven wrote:
> BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1865988
> 
> [Impact] 
> 
> The USB and HD audio controllers on 3rd-gen AMD Ryzen and Threadripper CPUs 
> advertise Function Level Reset.
> 
> However, after invoking this the CPU becomes unstable and within minutes crashes
> 
> [Test Case]
> 
>  Requires a machine with a 3rd-gen Ryzen or Threadripper
> 
>  Invoke FLR on either of the affected CPU-provided controllers. For example, if lspci shows:
> 
>  	0d:00.3 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] Matisse USB 3.0 Host Controller [1022:149c]
> 	0d:00.4 Audio device [0403]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse HD Audio Controller [1022:1487]
> 
> 
> Then either of these will precipitate the issue:
> 
>   echo "1" > /sys/bus/pci/devices/0000:0d:00.3/reset
>   echo "1" > /sys/bus/pci/devices/0000:0d:00.4/reset
> 
> [Regression Potential] 
> 
> This is a new workaround.
> 
> [Other Info]
> 
> The main users of this FLR functionality are those that wish to passthrough the USB or HD audio controllers to
> a virtual machine from a Linux host.
> 
> 
> Marcos Scriven (1):
>   PCI: Avoid FLR for AMD Matisse HD Audio & USB 3.0
> 
>  drivers/pci/quirks.c | 18 ++++++++++++++----
>  1 file changed, 14 insertions(+), 4 deletions(-)
> 

Hi Marcos,

Thank you for submitting the patch for the Ubuntu kernel.

However, the same patch has been sent on another thread which covers all
of the affected series and is already being reviewed:

https://lists.ubuntu.com/archives/kernel-team/2020-June/110642.html

So I'm NAK'ing this thread.


Thanks,
Kleber