[1/3] drm/amd: Fix detection of _PR3 on the PCIe root port

Message ID 20230926225955.386553-2-mario.limonciello@amd.com
State New
Headers
Series Fix Navi3x boot and hotplug problems |

Commit Message

Mario Limonciello Sept. 26, 2023, 10:59 p.m. UTC
  On some systems with Navi3x dGPU will attempt to use BACO for runtime
PM but fails to resume properly.  This is because on these systems
the root port goes into D3cold which is incompatible with BACO.

This happens because in this case dGPU is connected to a bridge between
root port which causes BOCO detection logic to fail.  Fix the intent of
the logic by looking at root port, not the immediate upstream bridge for
_PR3.

Cc: stable@vger.kernel.org
Suggested-by: Jun Ma <Jun.Ma2@amd.com>
Tested-by: David Perry <David.Perry@amd.com>
Fixes: b10c1c5b3a4e ("drm/amdgpu: add check for ACPI power resources")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
  

Comments

Deucher, Alexander Sept. 28, 2023, 4:58 p.m. UTC | #1
[Public]

> -----Original Message-----
> From: Limonciello, Mario <Mario.Limonciello@amd.com>
> Sent: Tuesday, September 26, 2023 7:00 PM
> To: amd-gfx@lists.freedesktop.org; Sebastian Reichel <sre@kernel.org>;
> Deucher, Alexander <Alexander.Deucher@amd.com>
> Cc: linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org; Ma, Jun
> <Jun.Ma2@amd.com>; Limonciello, Mario <Mario.Limonciello@amd.com>
> Subject: [PATCH 1/3] drm/amd: Fix detection of _PR3 on the PCIe root port
>
> On some systems with Navi3x dGPU will attempt to use BACO for runtime PM
> but fails to resume properly.  This is because on these systems the root port
> goes into D3cold which is incompatible with BACO.
>
> This happens because in this case dGPU is connected to a bridge between root
> port which causes BOCO detection logic to fail.  Fix the intent of the logic by
> looking at root port, not the immediate upstream bridge for _PR3.
>
> Cc: stable@vger.kernel.org
> Suggested-by: Jun Ma <Jun.Ma2@amd.com>
> Tested-by: David Perry <David.Perry@amd.com>
> Fixes: b10c1c5b3a4e ("drm/amdgpu: add check for ACPI power resources")
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

Series is:
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index e4627d92e1d0..bad2b5577e96 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -2238,7 +2238,7 @@ static int amdgpu_device_ip_early_init(struct
> amdgpu_device *adev)
>               adev->flags |= AMD_IS_PX;
>
>       if (!(adev->flags & AMD_IS_APU)) {
> -             parent = pci_upstream_bridge(adev->pdev);
> +             parent = pcie_find_root_port(adev->pdev);
>               adev->has_pr3 = parent ? pci_pr3_present(parent) : false;
>       }
>
> --
> 2.34.1
  

Patch

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index e4627d92e1d0..bad2b5577e96 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -2238,7 +2238,7 @@  static int amdgpu_device_ip_early_init(struct amdgpu_device *adev)
 		adev->flags |= AMD_IS_PX;
 
 	if (!(adev->flags & AMD_IS_APU)) {
-		parent = pci_upstream_bridge(adev->pdev);
+		parent = pcie_find_root_port(adev->pdev);
 		adev->has_pr3 = parent ? pci_pr3_present(parent) : false;
 	}