| Message ID | 20231120101543.4369-2-quic_kangyang@quicinc.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | wifi: ath12k: support one MSI | expand |
On 11/20/2023 2:15 AM, Kang Yang wrote: > The reservation mode of interrupts in kernel assigns a dummy vector > when the interrupt is allocated and assigns a real vector when the > request_irq is called. The reservation mode helps to ease vector > pressure when devices with a large amount of queues/interrupts are > initialized, but only a minimal subset of those queues/interrupts > is actually used. > > So on reservation mode, the msi_data may change after request_irq is > called, then it will lead to spurious interrupt. But when VT-d in > BIOS is enabled and ath12k can get 32 MSI vectors, ath12k always get > the same msi_data before and after request_irq. > > So in case of one MSI vector, ath12k need read msi_data again after > request_irq is called, and then the correct msi_data is programmed > into WCN7850 hardware components. > > Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4 > > Signed-off-by: Kang Yang <quic_kangyang@quicinc.com> Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
diff --git a/drivers/net/wireless/ath/ath12k/pci.c b/drivers/net/wireless/ath/ath12k/pci.c index 3006cd3fbe11..c5bc9afaa9fc 100644 --- a/drivers/net/wireless/ath/ath12k/pci.c +++ b/drivers/net/wireless/ath/ath12k/pci.c @@ -708,6 +708,25 @@ static void ath12k_pci_msi_free(struct ath12k_pci *ab_pci) pci_free_irq_vectors(ab_pci->pdev); } +static int ath12k_pci_config_msi_data(struct ath12k_pci *ab_pci) +{ + struct msi_desc *msi_desc; + + msi_desc = irq_get_msi_desc(ab_pci->pdev->irq); + if (!msi_desc) { + ath12k_err(ab_pci->ab, "msi_desc is NULL!\n"); + pci_free_irq_vectors(ab_pci->pdev); + return -EINVAL; + } + + ab_pci->msi_ep_base_data = msi_desc->msg.data; + + ath12k_dbg(ab_pci->ab, ATH12K_DBG_PCI, "pci after request_irq msi_ep_base_data %d\n", + ab_pci->msi_ep_base_data); + + return 0; +} + static int ath12k_pci_claim(struct ath12k_pci *ab_pci, struct pci_dev *pdev) { struct ath12k_base *ab = ab_pci->ab; @@ -1286,6 +1305,17 @@ static int ath12k_pci_probe(struct pci_dev *pdev, goto err_ce_free; } + /* 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 + * as msi_data will configured to srngs. + */ + ret = ath12k_pci_config_msi_data(ab_pci); + if (ret) { + ath12k_err(ab, "failed to config msi_data: %d\n", ret); + goto err_free_irq; + } + ret = ath12k_core_init(ab); if (ret) { ath12k_err(ab, "failed to init core: %d\n", ret);
The reservation mode of interrupts in kernel assigns a dummy vector when the interrupt is allocated and assigns a real vector when the request_irq is called. The reservation mode helps to ease vector pressure when devices with a large amount of queues/interrupts are initialized, but only a minimal subset of those queues/interrupts is actually used. So on reservation mode, the msi_data may change after request_irq is called, then it will lead to spurious interrupt. But when VT-d in BIOS is enabled and ath12k can get 32 MSI vectors, ath12k always get the same msi_data before and after request_irq. So in case of one MSI vector, ath12k need read msi_data again after request_irq is called, and then the correct msi_data is programmed into WCN7850 hardware components. Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4 Signed-off-by: Kang Yang <quic_kangyang@quicinc.com> --- drivers/net/wireless/ath/ath12k/pci.c | 30 +++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)