b43: Use a threaded IRQ handler

Use a threaded IRQ handler to allow locking the mutex and
sleeping while executing an interrupt.
This removes usage of the irq_lock spinlock, but introduces
a new hardirq_lock, which is _only_ used for the PCI/SSB lowlevel
hard-irq handler. Sleeping busses (SDIO) will use mutex instead.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 8 insertions, 15 deletions

diff --git a/drivers/net/wireless/b43/b43.h b/drivers/net/wireless/b43/b43.h
index a1b3b731935b..d63af926d058 100644
--- a/drivers/net/wireless/b43/b43.h
+++ b/drivers/net/wireless/b43/b43.h
@@ -616,6 +616,12 @@ struct b43_wl {
         /* Pointer to the ieee80211 hardware data structure */
         struct ieee80211_hw *hw;
 
+        /* Global driver mutex. Every operation must run with this mutex locked. */
+        struct mutex mutex;
+        /* Hard-IRQ spinlock. This lock protects things used in the hard-IRQ
+         * handler, only. This basically is just the IRQ mask register. */
+        spinlock_t hardirq_lock;
+
         /* The number of queues that were registered with the mac80211 subsystem
          * initially. This is a backup copy of hw->queues in case hw->queues has
          * to be dynamically lowered at runtime (Firmware does not support QoS).
@@ -623,8 +629,6 @@ struct b43_wl {
          * from the mac80211 subsystem. */
         u16 mac80211_initially_registered_queues;
 
-        struct mutex mutex;
-        spinlock_t irq_lock;
         /* R/W lock for data transmission.
          * Transmissions on 2+ queues can run concurrently, but somebody else
          * might sync with TX by write_lock_irqsave()'ing. */
@@ -665,8 +669,7 @@ struct b43_wl {
         bool radiotap_enabled;
         bool radio_enabled;
 
-        /* The beacon we are currently using (AP or IBSS mode).
-         * This beacon stuff is protected by the irq_lock. */
+        /* The beacon we are currently using (AP or IBSS mode). */
         struct sk_buff *current_beacon;
         bool beacon0_uploaded;
         bool beacon1_uploaded;
@@ -754,14 +757,6 @@ enum {
                 smp_wmb();                                      \
                                         } while (0)
 
-/* XXX---   HOW LOCKING WORKS IN B43   ---XXX
- *
- * You should always acquire both, wl->mutex and wl->irq_lock unless:
- * - You don't need to acquire wl->irq_lock, if the interface is stopped.
- * - You don't need to acquire wl->mutex in the IRQ handler, IRQ tasklet
- *   and packet TX path (and _ONLY_ there.)
- */
-
 /* Data structure for one wireless device (802.11 core) */
 struct b43_wldev {
         struct ssb_device *dev;
@@ -807,14 +802,12 @@ struct b43_wldev {
         u32 dma_reason[6];
         /* The currently active generic-interrupt mask. */
         u32 irq_mask;
+
         /* Link Quality calculation context. */
         struct b43_noise_calculation noisecalc;
         /* if > 0 MAC is suspended. if == 0 MAC is enabled. */
         int mac_suspended;
 
-        /* Interrupt Service Routine tasklet (bottom-half) */
-        struct tasklet_struct isr_tasklet;
-
         /* Periodic tasks */
         struct delayed_work periodic_work;
         unsigned int periodic_state;