ath11k: get msi_data again after request_irq is called

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, so ath11k reads msi_data again after request_irq is called,
and then the correct msi_data is programmed into QCA6390 hardware
components. Without this change, spurious interrupt occurs in case of
one MSI vector. When VT-d in BIOS is enabled and ath11k can get 32 MSI
vectors, ath11k always get the same msi_data before and after request_irq,
that's why this change is only required when one MSI vector is to be
supported.

Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1

Signed-off-by: Carl Huang <cjhuang@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20211026041636.5008-1-bqiang@codeaurora.org

diff --git a/drivers/net/wireless/ath/ath11k/pci.c b/drivers/net/wireless/ath/ath11k/pci.c
index c2af8184e4a2f4817bbf3735c7fd4f7e7d73f66d..305aa7a72c59a5136a68c7738944369a7011cba2 100644 (file)
--- a/drivers/net/wireless/ath/ath11k/pci.c
+++ b/drivers/net/wireless/ath/ath11k/pci.c
@@ -933,6 +933,25 @@ static void ath11k_pci_free_msi(struct ath11k_pci *ab_pci)
        pci_free_irq_vectors(ab_pci->pdev);
 }
 
+static int ath11k_pci_config_msi_data(struct ath11k_pci *ab_pci)
+{
+       struct msi_desc *msi_desc;
+
+       msi_desc = irq_get_msi_desc(ab_pci->pdev->irq);
+       if (!msi_desc) {
+               ath11k_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;
+
+       ath11k_dbg(ab_pci->ab, ATH11K_DBG_PCI, "pci after request_irq msi_ep_base_data %d\n",
+                  ab_pci->msi_ep_base_data);
+
+       return 0;
+}
+
 static int ath11k_pci_claim(struct ath11k_pci *ab_pci, struct pci_dev *pdev)
 {
        struct ath11k_base *ab = ab_pci->ab;
@@ -1342,6 +1361,17 @@ static int ath11k_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 = ath11k_pci_config_msi_data(ab_pci);
+       if (ret) {
+               ath11k_err(ab, "failed to config msi_data: %d\n", ret);
+               goto err_free_irq;
+       }
+
        ret = ath11k_core_init(ab);
        if (ret) {
                ath11k_err(ab, "failed to init core: %d\n", ret);