On 2024-11-05 20:19, Ramesh Errabolu wrote:
> Raise an info message in kernel log if PCIe root complex
> determines that a AMD GPU device D<i> cannot have P2P
> communication with another AMD GPU device D<j>
>
> Signed-off-by: Ramesh Errabolu <ramesh.errab...@amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 230c24638a34..ab304a2c4aaf 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -6222,6 +6222,8 @@ bool amdgpu_device_is_peer_accessible(struct
> amdgpu_device *adev,
> bool p2p_access =
> !adev->gmc.xgmi.connected_to_cpu &&
> !(pci_p2pdma_distance(adev->pdev, peer_adev->dev, false) < 0);
> + if (!p2p_access)
> + pr_info("PCIe based P2P links are not available\n");
This message would be a lot more useful if it told you, which two devices are
affected. You can use dev_info to have it print the PCIe BDF of adev. Then you
only need to print additional information for peer_adev using
pci_name(peer_adev->pdev).
Alternatively, you can just set the last parameter of pci_p2pdma_distance to
"true". Although, that will produce more scary-looking warning messages. I
believe Lijo disabled that at some point because of that reason.
Regards,
Felix
>
> bool is_large_bar = adev->gmc.visible_vram_size &&
> adev->gmc.real_vram_size == adev->gmc.visible_vram_size;
