[PATCH] drm/amdgpu: Disable PCIe dynamic speed switching on Ryzen Pinnacle Ridge

[Mario Limonciello]

AMD Ryzen Pinnacle Ridge (Zen+, family 0x17 model 0x08) CPUs have
PCI controllers that don't support PCIe dynamic speed switching,
causing system freezes during GPU initialization when enabled.

Disable dynamic speed switching when this CPU is detected.

Assisted-by: Claude:sonnet
Fixes: 466a7d115326e ("drm/amd: Use the first non-dGPU PCI device for BW 
limits")
Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5436
Signed-off-by: Mario Limonciello <mario.limoncie...@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 27f7a841cd623..f8324712b712c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -1289,6 +1289,15 @@ static bool 
amdgpu_device_pcie_dynamic_switching_supported(struct amdgpu_device
 
        if (c->x86_vendor == X86_VENDOR_INTEL)
                return false;
+
+       /*
+        * AMD Ryzen Pinnacle Ridge (Zen+, family 0x17 model 0x08) CPUs don't
+        * support PCIe dynamic speed switching.
+        * https://gitlab.freedesktop.org/drm/amd/-/work_items/5436
+        */
+       if (c->x86_vendor == X86_VENDOR_AMD && c->x86 == 0x17 &&
+           c->x86_model == 0x08)
+               return false;
 #endif
        return true;
 }
-- 
2.43.0