The patch below does not apply to the 5.15-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 bca52455a3c07922ee976714b00563a13a29ab15 Mon Sep 17 00:00:00 2001 From: Lang Yu Lang.Yu@amd.com Date: Fri, 28 Jan 2022 18:24:53 +0800 Subject: [PATCH] drm/amdgpu: fix a potential GPU hang on cyan skillfish

We observed a GPU hang when querying GMC CG state(i.e., cat amdgpu_pm_info) on cyan skillfish. Acctually, cyan skillfish doesn't support any CG features.

Just prevent it from accessing GMC CG registers.

Signed-off-by: Lang Yu Lang.Yu@amd.com Reviewed-by: Lijo Lazar lijo.lazar@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c index 38bb42727715..a2f8ed0e6a64 100644 --- a/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c @@ -1140,6 +1140,9 @@ static void gmc_v10_0_get_clockgating_state(void *handle, u32 *flags) { struct amdgpu_device *adev = (struct amdgpu_device *)handle;

+ if (adev->ip_versions[GC_HWIP][0] == IP_VERSION(10, 1, 3)) + return; + adev->mmhub.funcs->get_clockgating(adev, flags);

if (adev->ip_versions[ATHUB_HWIP][0] >= IP_VERSION(2, 1, 0))