From: Carl Huang <[email protected]>
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 <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
---
drivers/net/wireless/ath/ath11k/pci.c | 30 +++++++++++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/drivers/net/wireless/ath/ath11k/pci.c b/drivers/net/wireless/ath/ath11k/pci.c
index 3d353e7c9d5c..8691e1649d6c 100644
--- a/drivers/net/wireless/ath/ath11k/pci.c
+++ b/drivers/net/wireless/ath/ath11k/pci.c
@@ -929,6 +929,25 @@ 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;
@@ -1328,6 +1347,17 @@ 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);
--
2.25.1
Baochen Qiang <[email protected]> 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, 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 <[email protected]>
> Signed-off-by: Kalle Valo <[email protected]>
7 patches applied to ath-next branch of ath.git, thanks.
87b4072d7ef8 ath11k: get msi_data again after request_irq is called
01279bcd01d9 ath11k: add CE and ext IRQ flag to indicate irq_handler
4ab4693f327a ath11k: use ATH11K_PCI_IRQ_DP_OFFSET for DP IRQ
c41a6700b276 ath11k: refactor multiple MSI vector implementation
ac6e73483f7b ath11k: add support one MSI vector
915a081ff307 ath11k: do not restore ASPM in case of single MSI vector
e94b07493da3 ath11k: Set IRQ affinity to CPU0 in case of one MSI vector
--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches