[PATCH 14/18] drm/amdgpu: Fix amdgpu reload failure under SRIOV

[Christian König]

Am 18.09.2017 um 08:11 schrieb Monk Liu:
> From: Horace Chen <horace.chen at amd.com>
>
> Kernel will set the PCI power state to UNKNOWN after unloading,
> Since SRIOV has faked PCI config space so the UNKNOWN state
> will be kept forever.
>
> In driver reload if the power state is UNKNOWN then enabling msi
> will fail.
>
> forcely set it to D0 for SRIOV to fix this kernel flawness.
>
> Change-Id: I6a72d5fc9b653b21c3c98167515a511c5edeb91c
> Signed-off-by: Horace Chen <horace.chen at amd.com>
> Signed-off-by: Monk Liu <Monk.Liu at amd.com>

Acked-by: Christian König <christian.koenig at amd.com>, but better wait 
for Alex to have a look as well on this before pushing it.

Christian.

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | 10 +++++++++-
>   1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> index 914c5bf..345406a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> @@ -229,7 +229,15 @@ int amdgpu_irq_init(struct amdgpu_device *adev)
>   	adev->irq.msi_enabled = false;
>   
>   	if (amdgpu_msi_ok(adev)) {
> -		int ret = pci_enable_msi(adev->pdev);
> +		int ret;
> +		if (amdgpu_sriov_vf(adev) &&
> +		    adev->pdev->current_state == PCI_UNKNOWN){
> +			/* If pci power state is unknown on the SRIOV platform,
> +			 * it may be set in the remove device. We need to forcely
> +			 * set it to D0 to enable the msi*/
> +			adev->pdev->current_state = PCI_D0;
> +		}
> +		ret = pci_enable_msi(adev->pdev);
>   		if (!ret) {
>   			adev->irq.msi_enabled = true;
>   			dev_info(adev->dev, "amdgpu: using MSI.\n");