[PATCH v2] wifi: ath11k: fix boot failure with one MSI vector

[Jeff Johnson]

On 9/6/2023 6:56 PM, Baochen Qiang wrote:
> Commit 5b32b6dd96633 ("ath11k: Remove core PCI references from
> PCI common code") breaks with one MSI vector because it moves
> affinity setting after IRQ request, see below log:
> 
> [ 1417.278835] ath11k_pci 0000:02:00.0: failed to receive control response completion, polling..
> [ 1418.302829] ath11k_pci 0000:02:00.0: Service connect timeout
> [ 1418.302833] ath11k_pci 0000:02:00.0: failed to connect to HTT: -110
> [ 1418.303669] ath11k_pci 0000:02:00.0: failed to start core: -110
> 
> The detail is, if do affinity request after IRQ activated,
> which is done in request_irq(), kernel caches that request and
> returns success directly. Later when a subsequent MHI interrupt is
> fired, kernel will do the real affinity setting work, as a result,
> changs the MSI vector. However at that time host has configured
> old vector to hardware, so host never receives CE or DP interrupts.
> 
> Fix it by setting affinity before registering MHI controller
> where host is, for the first time, doing IRQ request.
> 
> Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3

Tested-on: WCN6855 hw2.1 PCI 
WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23
Tested-on: WCN6750 hw1.0 AHB WLAN.MSL.1.0.1-01160-QCAMSLSWPLZ-1

> 
> Fixes: 5b32b6dd9663 ("ath11k: Remove core PCI references from PCI common code")
> Signed-off-by: Baochen Qiang <quic_bqiang at quicinc.com>

Acked-by: Jeff Johnson <quic_jjohnson at quicinc.com>

> ---
> v2:
>   rebase on latest ath.git due to v1 apply failure.
> 
>   drivers/net/wireless/ath/ath11k/pci.c | 24 ++++++++++++------------
>   1 file changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath11k/pci.c b/drivers/net/wireless/ath/ath11k/pci.c
> index 9573bd959cac..aa049593f9b5 100644
> --- a/drivers/net/wireless/ath/ath11k/pci.c
> +++ b/drivers/net/wireless/ath/ath11k/pci.c
> @@ -852,10 +852,16 @@ static int ath11k_pci_probe(struct pci_dev *pdev,
>   	if (ret)
>   		goto err_pci_disable_msi;
>   
> +	ret = ath11k_pci_set_irq_affinity_hint(ab_pci, cpumask_of(0));
> +	if (ret) {
> +		ath11k_err(ab, "failed to set irq affinity %d\n", ret);
> +		goto err_pci_disable_msi;
> +	}
> +
>   	ret = ath11k_mhi_register(ab_pci);
>   	if (ret) {
>   		ath11k_err(ab, "failed to register mhi: %d\n", ret);
> -		goto err_pci_disable_msi;
> +		goto err_irq_affinity_cleanup;
>   	}
>   
>   	ret = ath11k_hal_srng_init(ab);
> @@ -876,12 +882,6 @@ static int ath11k_pci_probe(struct pci_dev *pdev,
>   		goto err_ce_free;
>   	}
>   
> -	ret = ath11k_pci_set_irq_affinity_hint(ab_pci, cpumask_of(0));
> -	if (ret) {
> -		ath11k_err(ab, "failed to set irq affinity %d\n", ret);
> -		goto err_free_irq;
> -	}
> -
>   	/* kernel may allocate a dummy vector before request_irq and
>   	 * then allocate a real vector when request_irq is called.
>   	 * So get msi_data here again to avoid spurious interrupt
> @@ -890,20 +890,17 @@ static int ath11k_pci_probe(struct pci_dev *pdev,
>   	ret = ath11k_pci_config_msi_data(ab_pci);
>   	if (ret) {
>   		ath11k_err(ab, "failed to config msi_data: %d\n", ret);
> -		goto err_irq_affinity_cleanup;
> +		goto err_free_irq;
>   	}
>   
>   	ret = ath11k_core_init(ab);
>   	if (ret) {
>   		ath11k_err(ab, "failed to init core: %d\n", ret);
> -		goto err_irq_affinity_cleanup;
> +		goto err_free_irq;
>   	}
>   	ath11k_qmi_fwreset_from_cold_boot(ab);
>   	return 0;
>   
> -err_irq_affinity_cleanup:
> -	ath11k_pci_set_irq_affinity_hint(ab_pci, NULL);
> -
>   err_free_irq:
>   	ath11k_pcic_free_irq(ab);
>   
> @@ -916,6 +913,9 @@ static int ath11k_pci_probe(struct pci_dev *pdev,
>   err_mhi_unregister:
>   	ath11k_mhi_unregister(ab_pci);
>   
> +err_irq_affinity_cleanup:
> +	ath11k_pci_set_irq_affinity_hint(ab_pci, NULL);
> +
>   err_pci_disable_msi:
>   	ath11k_pci_free_msi(ab_pci);
>   
> 
> base-commit: 0263687f4441d5a5eab8074d56b4693c8f0acf85