[PATCH] rtlwifi: rtl8192x: Enabling and disabling hardware interrupts after enabling local irq flags

From: Bharat Kumar Gogada
Date: Thu Jan 19 2017 - 05:31:00 EST


-Realtek 8192CE chipset maintains local irq flags after enabling/disabling
hardware interrupts.
-Hardware interrupts are enabled before enabling the local irq
flags(these flags are being checked in interrupt handler),
leading to race condition on some RP, where the irq line between
bridge and GIC goes high at ASSERT_INTx and goes low only
at DEASSERT_INTx. In this kind of RP by the time ASSERT_INTx is seen
irq_enable flag is still set to false, resulting in continuous
interrupts seen by CPU as DEASSERT_INTx cannot be sent since
flag is still false and making CPU stall.
-Changing the sequence of setting these irq flags.

Signed-off-by: Bharat Kumar Gogada <bharatku@xxxxxxxxxx>
---
drivers/net/wireless/realtek/rtlwifi/rtl8192ce/hw.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/hw.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/hw.c
index a47be73..143766c4 100644
--- a/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/hw.c
+++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192ce/hw.c
@@ -1306,9 +1306,9 @@ void rtl92ce_enable_interrupt(struct ieee80211_hw *hw)
struct rtl_priv *rtlpriv = rtl_priv(hw);
struct rtl_pci *rtlpci = rtl_pcidev(rtl_pcipriv(hw));

+ rtlpci->irq_enabled = true;
rtl_write_dword(rtlpriv, REG_HIMR, rtlpci->irq_mask[0] & 0xFFFFFFFF);
rtl_write_dword(rtlpriv, REG_HIMRE, rtlpci->irq_mask[1] & 0xFFFFFFFF);
- rtlpci->irq_enabled = true;
}

void rtl92ce_disable_interrupt(struct ieee80211_hw *hw)
@@ -1316,9 +1316,9 @@ void rtl92ce_disable_interrupt(struct ieee80211_hw *hw)
struct rtl_priv *rtlpriv = rtl_priv(hw);
struct rtl_pci *rtlpci = rtl_pcidev(rtl_pcipriv(hw));

+ rtlpci->irq_enabled = false;
rtl_write_dword(rtlpriv, REG_HIMR, IMR8190_DISABLED);
rtl_write_dword(rtlpriv, REG_HIMRE, IMR8190_DISABLED);
- rtlpci->irq_enabled = false;
}

static void _rtl92ce_poweroff_adapter(struct ieee80211_hw *hw)
--
2.1.1