[PATCH 7/7] ath11k: Set IRQ affinity to CPU0 in case of one MSI vector

[Kalle Valo]

Baochen Qiang <bqiang at codeaurora.org> writes:

> With VT-d disabled on Intel platform, ath11k gets only one MSI
> vector. In that case, ath11k does not free IRQ when doing suspend,
> hence the kernel has to migrate it to CPU0 (if it was affine to
> other CPUs) and allocates a new MSI vector. However, ath11k has
> no chance to reconfig it to HW srngs during this phase, thus
> ath11k fails to resume.
>
> This issue can be fixed by setting IRQ affinity to CPU0 before
> request_irq is called. With such affinity, migration will not
> happen and thus the vector keeps unchanged during suspend/resume.
>
> Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1
>
> Signed-off-by: Baochen Qiang <bqiang at codeaurora.org>
> ---
>  drivers/net/wireless/ath/ath11k/pci.c | 24 ++++++++++++++++++++++--
>  1 file changed, 22 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath11k/pci.c b/drivers/net/wireless/ath/ath11k/pci.c
> index b450b4ed35d1..1cad7545ceb9 100644
> --- a/drivers/net/wireless/ath/ath11k/pci.c
> +++ b/drivers/net/wireless/ath/ath11k/pci.c
> @@ -840,6 +840,14 @@ static int ath11k_pci_ext_irq_config(struct ath11k_base *ab)
>  	return 0;
>  }
>  
> +static int ath11k_pci_set_irq_affinity_hint(struct ath11k_pci *ab_pci, const struct cpumask *m)
> +{
> +	if (!test_bit(ATH11K_PCI_FLAG_MULTI_MSI_VECTORS, &ab_pci->flags))
> +		return irq_set_affinity_hint(ab_pci->pdev->irq, m);
> +
> +	return 0;
> +}

I reversed the order here:

static int ath11k_pci_set_irq_affinity_hint(struct ath11k_pci *ab_pci,
					    const struct cpumask *m)
{
	if (test_bit(ATH11K_PCI_FLAG_MULTI_MSI_VECTORS, &ab_pci->flags))
		return 0;

	return irq_set_affinity_hint(ab_pci->pdev->irq, m);
}

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