If a shared IRQ is used by the driver due to platform limitation, then the
IRQ affinity hint is set right after the allocation of IRQ vectors in
ath12k_pci_msi_alloc(). This does no harm unless one of the functions
requesting the IRQ fails and attempt to free the IRQ.

This may end up with a warning from the IRQ core that is expecting the
affinity hint to be cleared before freeing the IRQ:

kernel/irq/manage.c:

	/* make sure affinity_hint is cleaned up */
	if (WARN_ON_ONCE(desc->affinity_hint))
		desc->affinity_hint = NULL;

So to fix this issue, clear the IRQ affinity hint before calling
ath12k_pci_free_irq() in the error path. The affinity will be cleared once
again further down the error path due to code organization, but that does
no harm.

Fixes: a3012f206d07 ("wifi: ath12k: set IRQ affinity to CPU0 in case of one MSI vector")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/net/wireless/ath/ath12k/pci.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/wireless/ath/ath12k/pci.c b/drivers/net/wireless/ath/ath12k/pci.c
index 06cff3849ab8..2851f6944b86 100644
--- a/drivers/net/wireless/ath/ath12k/pci.c
+++ b/drivers/net/wireless/ath/ath12k/pci.c
@@ -1689,6 +1689,8 @@ static int ath12k_pci_probe(struct pci_dev *pdev,
 	return 0;
 
 err_free_irq:
+	/* __free_irq() expects the caller to have cleared the affinity hint */
+	ath12k_pci_set_irq_affinity_hint(ab_pci, NULL);
 	ath12k_pci_free_irq(ab);
 
 err_ce_free:
-- 
2.25.1

On 2/25/2025 1:34 PM, Manivannan Sadhasivam wrote:
> If a shared IRQ is used by the driver due to platform limitation, then the
> IRQ affinity hint is set right after the allocation of IRQ vectors in
> ath12k_pci_msi_alloc(). This does no harm unless one of the functions
> requesting the IRQ fails and attempt to free the IRQ.
> 
> This may end up with a warning from the IRQ core that is expecting the
> affinity hint to be cleared before freeing the IRQ:
> 
> kernel/irq/manage.c:
> 
> 	/* make sure affinity_hint is cleaned up */
> 	if (WARN_ON_ONCE(desc->affinity_hint))
> 		desc->affinity_hint = NULL;
> 
> So to fix this issue, clear the IRQ affinity hint before calling
> ath12k_pci_free_irq() in the error path. The affinity will be cleared once
> again further down the error path due to code organization, but that does
> no harm.
> 
> Fixes: a3012f206d07 ("wifi: ath12k: set IRQ affinity to CPU0 in case of one MSI vector")
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  drivers/net/wireless/ath/ath12k/pci.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/wireless/ath/ath12k/pci.c b/drivers/net/wireless/ath/ath12k/pci.c
> index 06cff3849ab8..2851f6944b86 100644
> --- a/drivers/net/wireless/ath/ath12k/pci.c
> +++ b/drivers/net/wireless/ath/ath12k/pci.c
> @@ -1689,6 +1689,8 @@ static int ath12k_pci_probe(struct pci_dev *pdev,
>  	return 0;
>  
>  err_free_irq:
> +	/* __free_irq() expects the caller to have cleared the affinity hint */
> +	ath12k_pci_set_irq_affinity_hint(ab_pci, NULL);
>  	ath12k_pci_free_irq(ab);
>  
>  err_ce_free:

Reviewed-by: Baochen Qiang <quic_bqiang@quicinc.com>

On 2/25/2025 1:34 PM, Manivannan Sadhasivam wrote:
> If a shared IRQ is used by the driver due to platform limitation, then the
> IRQ affinity hint is set right after the allocation of IRQ vectors in
> ath12k_pci_msi_alloc(). This does no harm unless one of the functions
> requesting the IRQ fails and attempt to free the IRQ.
> 
> This may end up with a warning from the IRQ core that is expecting the
> affinity hint to be cleared before freeing the IRQ:
> 
> kernel/irq/manage.c:
> 
> 	/* make sure affinity_hint is cleaned up */
> 	if (WARN_ON_ONCE(desc->affinity_hint))
> 		desc->affinity_hint = NULL;
> 
> So to fix this issue, clear the IRQ affinity hint before calling
> ath12k_pci_free_irq() in the error path. The affinity will be cleared once
> again further down the error path due to code organization, but that does
> no harm.
> 
> Fixes: a3012f206d07 ("wifi: ath12k: set IRQ affinity to CPU0 in case of one MSI vector")
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  drivers/net/wireless/ath/ath12k/pci.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/wireless/ath/ath12k/pci.c b/drivers/net/wireless/ath/ath12k/pci.c
> index 06cff3849ab8..2851f6944b86 100644
> --- a/drivers/net/wireless/ath/ath12k/pci.c
> +++ b/drivers/net/wireless/ath/ath12k/pci.c
> @@ -1689,6 +1689,8 @@ static int ath12k_pci_probe(struct pci_dev *pdev,
>  	return 0;
>  
>  err_free_irq:
> +	/* __free_irq() expects the caller to have cleared the affinity hint */
> +	ath12k_pci_set_irq_affinity_hint(ab_pci, NULL);
>  	ath12k_pci_free_irq(ab);
>  
>  err_ce_free:

LGTM