[PATCH v4] drm/amdgpu: Restore msix after FLR

[Christian König]

Am 02.07.21 um 05:23 schrieb Peng Ju Zhou:
> From: "Emily.Deng" <Emily.Deng at amd.com>
>
> After FLR, the msix will be cleared, so need to re-enable it.
>
> Signed-off-by: Emily.Deng <Emily.Deng at amd.com>
> Signed-off-by: Peng Ju Zhou <PengJu.Zhou at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | 14 ++++++++++++++
>   1 file changed, 14 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> index 90f50561b43a..034420c38352 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> @@ -277,6 +277,19 @@ static bool amdgpu_msi_ok(struct amdgpu_device *adev)
>   	return true;
>   }
>   
> +void amdgpu_restore_msix(struct amdgpu_device *adev)

I think this function should be static and maybe add a one line comment 
like "Clear and re-set the MSIX flags if they where set before to 
trigger re-enabling it".

With that done feel free to add an Acked-by: Christian König 
<christian.koenig at amd.com>, but I would also wait what Alex has to say 
about that.

Regards,
Christian

> +{
> +	u16 ctrl;
> +
> +	pci_read_config_word(adev->pdev, adev->pdev->msix_cap + PCI_MSIX_FLAGS, &ctrl);
> +	if (!(ctrl & PCI_MSIX_FLAGS_ENABLE))
> +		return;
> +
> +	ctrl &= ~PCI_MSIX_FLAGS_ENABLE;
> +	pci_write_config_word(adev->pdev, adev->pdev->msix_cap + PCI_MSIX_FLAGS, ctrl);
> +	ctrl |= PCI_MSIX_FLAGS_ENABLE;
> +	pci_write_config_word(adev->pdev, adev->pdev->msix_cap + PCI_MSIX_FLAGS, ctrl);
> +}
>   /**
>    * amdgpu_irq_init - initialize interrupt handling
>    *
> @@ -558,6 +571,7 @@ void amdgpu_irq_gpu_reset_resume_helper(struct amdgpu_device *adev)
>   {
>   	int i, j, k;
>   
> +	amdgpu_restore_msix(adev);
>   	for (i = 0; i < AMDGPU_IRQ_CLIENTID_MAX; ++i) {
>   		if (!adev->irq.client[i].sources)
>   			continue;