[PATCH v2] drm/amd: Add pre-zen AMD hardware to PCIe dynamic switching exclusions

[Leo]

Em 03/04/2025 00:11, Mario Limonciello escreveu:
> From: Mario Limonciello <mario.limonciello at amd.com>
> 
> AMD RX580 when added AMD Phenom 2 has problems with overheating. This is due to
> changes with PCIe dynamic switching introduced by commit 466a7d115326e
> ("drm/amd: Use the first non-dGPU PCI device for BW limits").
> 
> To avoid risks of other issues with old hardware require at least Zen hardware
> for AMD side to enable PCIe dynamic switching.
> 
> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4098
> Fixes: 466a7d115326e ("drm/amd: Use the first non-dGPU PCI device for BW limits")
> Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>
> ---
> v2:
>   * Cover more hardware
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index a30111d2c3ea0..caa44ee788c8f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -1854,6 +1854,9 @@ bool amdgpu_device_seamless_boot_supported(struct amdgpu_device *adev)
>    *
>    * https://edc.intel.com/content/www/us/en/design/products/platforms/details/raptor-lake-s/13th-generation-core-processors-datasheet-volume-1-of-2/005/pci-express-support/
>    * https://gitlab.freedesktop.org/drm/amd/-/issues/2663
> + *
> + * AMD Phenom II X6 1090T has a similar issue
> + * https://gitlab.freedesktop.org/drm/amd/-/issues/4098
>    */
>   static bool amdgpu_device_pcie_dynamic_switching_supported(struct amdgpu_device *adev)
>   {
> @@ -1866,6 +1869,8 @@ static bool amdgpu_device_pcie_dynamic_switching_supported(struct amdgpu_device
>   
>   	if (c->x86_vendor == X86_VENDOR_INTEL)
>   		return false;
> +	if (c->x86_vendor == X86_VENDOR_AMD && !cpu_feature_enabled(X86_FEATURE_ZEN))
> +		return false;
>   #endif
>   	return true;
>   }

I was able to test and confirm that this patch solve the issue 4098 on upstream linux kernel git. I could check that backporting it to LTS stable branch 6.12 solve the issue with this series too. Tested on AMD 880G chipset, Phenom II x6 1090T processor with AMD Radeon RX 580 GPU.

Tested-by: Leandro Pinheiro <leo.cod at cardosozeferino.com>