The patch below does not apply to the 4.16-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 589941e1a2d65f5425c91a5859a5454df64b6982 Mon Sep 17 00:00:00 2001

From: Rex Zhu Rex.Zhu@amd.com Date: Tue, 27 Feb 2018 18:20:53 +0800 Subject: [PATCH] drm/amdgpu: Notify sbios device ready before send request

it is required if a platform supports PCIe root complex core voltage reduction. After receiving this notification, SBIOS can apply default PCIe root complex power policy.

Reviewed-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Rex Zhu Rex.Zhu@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c index 57afad79f55d..8fa850a070e0 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c @@ -540,6 +540,9 @@ int amdgpu_acpi_pcie_performance_request(struct amdgpu_device *adev, size_t size; u32 retry = 3;

+ if (amdgpu_acpi_pcie_notify_device_ready(adev)) + return -EINVAL; + /* Get the device handle */ handle = ACPI_HANDLE(&adev->pdev->dev); if (!handle)