[PATCH v3 1/2] rtlwifi: add MSI interrupts mode support

Adam Lee
2014-03-28T03:36:31Z

Add MSI interrupts mode support, enable it when submodules' msi_support
flag is true, also could fallback to pin-based interrupts mode if MSI
interrupts mode fails.

RealTek's policy(on modules which work well with MSI interrupts mode) is:

> If the platform supports both MSI and pin-based, use MSI.
> If the platform supports MSI only, use MSI.
> If the platform supports pin-based only, use pin-based.

Also as RealTek's testing results, RTL8188EE and RTL8723BE work well
with both MSI mode and pin-based mode fallback.

Signed-off-by: Adam Lee <adam.lee@canonical.com>
---
drivers/net/wireless/rtlwifi/pci.c | 65 ++++++++++++++++++++++++++++++++++++--
1 file changed, 63 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/rtlwifi/pci.c b/drivers/net/wireless/rtlwifi/pci.c
index 7d71170..dae5525 100644
--- a/drivers/net/wireless/rtlwifi/pci.c
+++ b/drivers/net/wireless/rtlwifi/pci.c
@@ -1853,6 +1853,65 @@ static bool _rtl_pci_find_adapter(struct pci_dev *pdev,
return true;
}

+static int rtl_pci_intr_mode_msi(struct ieee80211_hw *hw)
+{
+ struct rtl_priv *rtlpriv = rtl_priv(hw);
+ struct rtl_pci_priv *pcipriv = rtl_pcipriv(hw);
+ struct rtl_pci *rtlpci = rtl_pcidev(pcipriv);
+ int ret;
+
+ ret = pci_enable_msi(rtlpci->pdev);
+ if (ret < 0)
+ return ret;
+
+ ret = request_irq(rtlpci->pdev->irq, &_rtl_pci_interrupt,
+ IRQF_SHARED, KBUILD_MODNAME, hw);
+ if (ret < 0) {
+ pci_disable_msi(rtlpci->pdev);
+ return ret;
+ }
+
+ rtlpci->using_msi = true;
+
+ RT_TRACE(rtlpriv, COMP_INIT|COMP_INTR, DBG_DMESG,
+ "MSI Interrupt Mode!\n");
+ return 0;
+}
+
+static int rtl_pci_intr_mode_legacy(struct ieee80211_hw *hw)
+{
+ struct rtl_priv *rtlpriv = rtl_priv(hw);
+ struct rtl_pci_priv *pcipriv = rtl_pcipriv(hw);
+ struct rtl_pci *rtlpci = rtl_pcidev(pcipriv);
+ int ret;
+
+ ret = request_irq(rtlpci->pdev->irq, &_rtl_pci_interrupt,
+ IRQF_SHARED, KBUILD_MODNAME, hw);
+ if (ret < 0)
+ return ret;
+
+ rtlpci->using_msi = false;
+ RT_TRACE(rtlpriv, COMP_INIT|COMP_INTR, DBG_DMESG,
+ "Pin-based Interrupt Mode!\n");
+ return 0;
+}
+
+static int rtl_pci_intr_mode_decide(struct ieee80211_hw *hw)
+{
+ struct rtl_pci_priv *pcipriv = rtl_pcipriv(hw);
+ struct rtl_pci *rtlpci = rtl_pcidev(pcipriv);
+ int ret;
+
+ if (rtlpci->msi_support) {
+ ret = rtl_pci_intr_mode_msi(hw);
+ if (ret < 0)
+ ret = rtl_pci_intr_mode_legacy(hw);
+ } else {
+ ret = rtl_pci_intr_mode_legacy(hw);
+ }
+ return ret;
+}
+
int rtl_pci_probe(struct pci_dev *pdev,
const struct pci_device_id *id)
{
@@ -1995,8 +2054,7 @@ int rtl_pci_probe(struct pci_dev *pdev,
}

rtlpci = rtl_pcidev(pcipriv);
- err = request_irq(rtlpci->pdev->irq, &_rtl_pci_interrupt,
- IRQF_SHARED, KBUILD_MODNAME, hw);
+ err = rtl_pci_intr_mode_decide(hw);
if (err) {
RT_TRACE(rtlpriv, COMP_INIT, DBG_DMESG,
"%s: failed to register IRQ handler\n",
@@ -2064,6 +2122,9 @@ void rtl_pci_disconnect(struct pci_dev *pdev)
rtlpci->irq_alloc = 0;
}

+ if (rtlpci->using_msi)
+ pci_disable_msi(rtlpci->pdev);
+
list_del(&rtlpriv->list);
if (rtlpriv->io.pci_mem_start != 0) {
pci_iounmap(pdev, (void __iomem *)rtlpriv->io.pci_mem_start);
--
1.9.1