mwifiex: access interrupt status only while holding lock

This patch fixes a bug for few instances where PCIe interrupt
status variable is accessed without holding spin lock.
This can result into missing interrupts.

Fix this by copying interrupt status to a local variable and
then using it for calling specific routine.

Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 12 insertions, 13 deletions

diff --git a/drivers/net/wireless/mwifiex/pcie.c b/drivers/net/wireless/mwifiex/pcie.c
index 13fbc4eb1595..e4c2cfdd049c 100644
--- a/drivers/net/wireless/mwifiex/pcie.c
+++ b/drivers/net/wireless/mwifiex/pcie.c
@@ -1594,39 +1594,40 @@ exit:
 static int mwifiex_process_int_status(struct mwifiex_adapter *adapter)
 {
         int ret;
-        u32 pcie_ireg = 0;
+        u32 pcie_ireg;
         unsigned long flags;
 
         spin_lock_irqsave(&adapter->int_lock, flags);
         /* Clear out unused interrupts */
-        adapter->int_status &= HOST_INTR_MASK;
+        pcie_ireg = adapter->int_status;
+        adapter->int_status = 0;
         spin_unlock_irqrestore(&adapter->int_lock, flags);
 
-        while (adapter->int_status & HOST_INTR_MASK) {
-                if (adapter->int_status & HOST_INTR_DNLD_DONE) {
-                        adapter->int_status &= ~HOST_INTR_DNLD_DONE;
+        while (pcie_ireg & HOST_INTR_MASK) {
+                if (pcie_ireg & HOST_INTR_DNLD_DONE) {
+                        pcie_ireg &= ~HOST_INTR_DNLD_DONE;
                         if (adapter->data_sent) {
                                 dev_dbg(adapter->dev, "info: DATA sent intr\n");
                                 adapter->data_sent = false;
                         }
                 }
-                if (adapter->int_status & HOST_INTR_UPLD_RDY) {
-                        adapter->int_status &= ~HOST_INTR_UPLD_RDY;
+                if (pcie_ireg & HOST_INTR_UPLD_RDY) {
+                        pcie_ireg &= ~HOST_INTR_UPLD_RDY;
                         dev_dbg(adapter->dev, "info: Rx DATA\n");
                         ret = mwifiex_pcie_process_recv_data(adapter);
                         if (ret)
                                 return ret;
                 }
-                if (adapter->int_status & HOST_INTR_EVENT_RDY) {
-                        adapter->int_status &= ~HOST_INTR_EVENT_RDY;
+                if (pcie_ireg & HOST_INTR_EVENT_RDY) {
+                        pcie_ireg &= ~HOST_INTR_EVENT_RDY;
                         dev_dbg(adapter->dev, "info: Rx EVENT\n");
                         ret = mwifiex_pcie_process_event_ready(adapter);
                         if (ret)
                                 return ret;
                 }
 
-                if (adapter->int_status & HOST_INTR_CMD_DONE) {
-                        adapter->int_status &= ~HOST_INTR_CMD_DONE;
+                if (pcie_ireg & HOST_INTR_CMD_DONE) {
+                        pcie_ireg &= ~HOST_INTR_CMD_DONE;
                         if (adapter->cmd_sent) {
                                 dev_dbg(adapter->dev,
                                         "info: CMD sent Interrupt\n");
@@ -1654,8 +1655,6 @@ static int mwifiex_process_int_status(struct mwifiex_adapter *adapter)
                                                  "Write register failed\n");
                                         return -1;
                                 }
-                                adapter->int_status |= pcie_ireg;
-                                adapter->int_status &= HOST_INTR_MASK;
                         }
 
                 }