[PATCH v2 2/2] drm/amd: Exclude dGPUs in eGPU enclosures from DPM quirks

[Mario Limonciello]

The PCIe speed capabilities advertised by a USB4 or TBT3 link are
limited to PCIe gen 1 per the USB4 spec. In reality the speed will
change dynamically based on fabric conditions and other traffic.

DPM is disabled when dGPUs are connected directly to Intel hosts
since the PCIe root port isn't able to handle dynamic speed
switching.

As this limitation is specifically for PCIe root ports in the SoC,
don't apply it when connected to an eGPU enclosure connected to an
Intel host.

Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2885
Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>
---
v1->v2:
 * Adjust commit message
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 683ea2284827..b49ad7690a8c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -1551,11 +1551,15 @@ 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
  */
-static bool amdgpu_device_pcie_dynamic_switching_supported(void)
+static bool amdgpu_device_pcie_dynamic_switching_supported(struct amdgpu_device *adev)
 {
 #if IS_ENABLED(CONFIG_X86)
 	struct cpuinfo_x86 *c = &cpu_data(0);
 
+	/* eGPU change speeds based on USB4 fabric conditions */
+	if (dev_is_removable(adev->dev))
+		return true;
+
 	if (c->x86_vendor == X86_VENDOR_INTEL)
 		return false;
 #endif
@@ -2395,7 +2399,7 @@ static int amdgpu_device_ip_early_init(struct amdgpu_device *adev)
 		adev->pm.pp_feature &= ~PP_GFXOFF_MASK;
 	if (amdgpu_sriov_vf(adev) && adev->asic_type == CHIP_SIENNA_CICHLID)
 		adev->pm.pp_feature &= ~PP_OVERDRIVE_MASK;
-	if (!amdgpu_device_pcie_dynamic_switching_supported())
+	if (!amdgpu_device_pcie_dynamic_switching_supported(adev))
 		adev->pm.pp_feature &= ~PP_PCIE_DPM_MASK;
 
 	total = true;
-- 
2.34.1