rt2x00: Revise irqmask locking for PCI devices

The PCI device irqmask is locked by a spin_lock. Currently
spin_lock_irqsave is used everywhere. To reduce the locking overhead
replace spin_lock_irqsave in hard irq context with spin_lock and in
soft irq context with spin_lock_irq.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 6 insertions, 9 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2400pci.c b/drivers/net/wireless/rt2x00/rt2400pci.c
index 9016c00f2946..80f4988adf80 100644
--- a/drivers/net/wireless/rt2x00/rt2400pci.c
+++ b/drivers/net/wireless/rt2x00/rt2400pci.c
@@ -1317,27 +1317,25 @@ static void rt2400pci_txdone(struct rt2x00_dev *rt2x00dev,
 static void rt2400pci_enable_interrupt(struct rt2x00_dev *rt2x00dev,
                                        struct rt2x00_field32 irq_field)
 {
-        unsigned long flags;
         u32 reg;
 
         /*
          * Enable a single interrupt. The interrupt mask register
          * access needs locking.
          */
-        spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+        spin_lock_irq(&rt2x00dev->irqmask_lock);
 
         rt2x00pci_register_read(rt2x00dev, CSR8, &reg);
         rt2x00_set_field32(&reg, irq_field, 0);
         rt2x00pci_register_write(rt2x00dev, CSR8, reg);
 
-        spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+        spin_unlock_irq(&rt2x00dev->irqmask_lock);
 }
 
 static void rt2400pci_txstatus_tasklet(unsigned long data)
 {
         struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data;
         u32 reg;
-        unsigned long flags;
 
         /*
          * Handle all tx queues.
@@ -1349,7 +1347,7 @@ static void rt2400pci_txstatus_tasklet(unsigned long data)
         /*
          * Enable all TXDONE interrupts again.
          */
-        spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+        spin_lock_irq(&rt2x00dev->irqmask_lock);
 
         rt2x00pci_register_read(rt2x00dev, CSR8, &reg);
         rt2x00_set_field32(&reg, CSR8_TXDONE_TXRING, 0);
@@ -1357,7 +1355,7 @@ static void rt2400pci_txstatus_tasklet(unsigned long data)
         rt2x00_set_field32(&reg, CSR8_TXDONE_PRIORING, 0);
         rt2x00pci_register_write(rt2x00dev, CSR8, reg);
 
-        spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+        spin_unlock_irq(&rt2x00dev->irqmask_lock);
 }
 
 static void rt2400pci_tbtt_tasklet(unsigned long data)
@@ -1378,7 +1376,6 @@ static irqreturn_t rt2400pci_interrupt(int irq, void *dev_instance)
 {
         struct rt2x00_dev *rt2x00dev = dev_instance;
         u32 reg, mask;
-        unsigned long flags;
 
         /*
          * Get the interrupt sources & saved to local variable.
@@ -1420,13 +1417,13 @@ static irqreturn_t rt2400pci_interrupt(int irq, void *dev_instance)
          * Disable all interrupts for which a tasklet was scheduled right now,
          * the tasklet will reenable the appropriate interrupts.
          */
-        spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+        spin_lock(&rt2x00dev->irqmask_lock);
 
         rt2x00pci_register_read(rt2x00dev, CSR8, &reg);
         reg |= mask;
         rt2x00pci_register_write(rt2x00dev, CSR8, reg);
 
-        spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+        spin_unlock(&rt2x00dev->irqmask_lock);