From 31b153315b8702d0249aa44d83d9fbf42c5c7a79 Mon Sep 17 00:00:00 2001 From: Perry Yuan Date: Wed, 28 Jan 2026 13:54:31 +0800 Subject: [PATCH] drm/amdgpu: ensure no_hw_access is visible before MMIO Add a full memory barrier after clearing no_hw_access in amdgpu_device_mode1_reset() so subsequent PCI state restore access cannot observe stale state on other CPUs. Fixes: 7edb503fe4b6 ("drm/amd/pm: Disable MMIO access during SMU Mode 1 reset") Signed-off-by: Perry Yuan Reviewed-by: Yifan Zhang Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index c7f44422939f7..c1ffc63e23ab5 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -5733,6 +5733,9 @@ int amdgpu_device_mode1_reset(struct amdgpu_device *adev) /* enable mmio access after mode 1 reset completed */ adev->no_hw_access = false; + /* ensure no_hw_access is updated before we access hw */ + smp_mb(); + amdgpu_device_load_pci_state(adev->pdev); ret = amdgpu_psp_wait_for_bootloader(adev); if (ret) -- 2.47.3