amdgpu vs kexec

[Peter Zijlstra]

On Mon, Jun 16, 2025 at 01:51:21PM +0200, Christian König wrote:
> Hi Peter,
> 
> On 6/16/25 11:39, Peter Zijlstra wrote:
> > Hi guys,
> > 
> > My (Intel Sapphire Rapids) workstation has a RX 7800 XT and when I kexec
> > a bunch of times, the amdgpu driver gets upset and barfs on boot.
> 
> yeah, that is an "intentional" HW feature and yes you're certainly not
> the first one to complain about it :(
> 
> The PSP (platform security processor IIRC) is designed in such a way
> that you can initialize it only once after a power cycle / hard reset
> for security reasons (e.g. to not leak crypto keys used for digital
> rights management etc..).
> 
> On dGPUs we work around that manually by power cycling the ASIC when
> that situation is detected during amdgpu load, but that unfortunately
> doesn't work 100% reliable.

Right.. hence the splats.

> On APUs the situation is even worse because the PSP is shared between
> the GPU and the CPU.
> 
> We have forwarded such complains internally for years, but there is
> not much else Alex and I can do about it.

Oh well. Thanks for the info!