The reservation mode of interrupts is 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@xxxxxxxxxxxxxx>
---
drivers/net/wireless/ath/ath11k/pci.c | 37 +++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)
diff --git a/drivers/net/wireless/ath/ath11k/pci.c b/drivers/net/wireless/ath/ath11k/pci.c
index 78478b2..c1ae1df 100644
--- a/drivers/net/wireless/ath/ath11k/pci.c
+++ b/drivers/net/wireless/ath/ath11k/pci.c
@@ -804,6 +804,32 @@ static void ath11k_pci_disable_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;
+ int ret;
+
+ msi_desc = irq_get_msi_desc(ab_pci->pdev->irq);
+ if (!msi_desc) {
+ ath11k_err(ab_pci->ab, "%s msi_desc is NULL!\n", __func__);
+ ret = -EINVAL;
+ goto free_msi_vector;
+ }
+
+ ab_pci->msi_ep_base_data = msi_desc->msg.data;
+
+ ath11k_dbg(ab_pci->ab, ATH11K_DBG_PCI,
+ "msi base data after request_irq is %d\n",
+ ab_pci->msi_ep_base_data);
+
+ return 0;
+
+free_msi_vector:
+ pci_free_irq_vectors(ab_pci->pdev);
+
+ return ret;
+}
+
static int ath11k_pci_claim(struct ath11k_pci *ab_pci, struct pci_dev *pdev)
{
struct ath11k_base *ab = ab_pci->ab;
@@ -1174,6 +1200,17 @@ 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_ce_free;
+ }
+
ret = ath11k_core_init(ab);
if (ret) {
ath11k_err(ab, "failed to init core: %d\n", ret);
--
2.7.4
