ath5k: fix suspend-related oops on rmmod

Based on a patch by Elias Oltmanns, we call ath5k_init in resume even
if we didn't previously open the device.  Besides starting up the
device unnecessarily, this also causes an oops on rmmod because
mac80211 will not invoke ath5k_stop and softirqs are left running after
the module has been unloaded.  Add a new state bit, ATH_STAT_STARTED,
to indicate that we have been started up.

Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Elias Oltmanns <eo@nebensachen.de>
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Cc: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 21 insertions, 9 deletions

diff --git a/drivers/net/wireless/ath5k/base.c b/drivers/net/wireless/ath5k/base.c
index 9b95c4049b31..0f1d6bdd51a2 100644
--- a/drivers/net/wireless/ath5k/base.c
+++ b/drivers/net/wireless/ath5k/base.c
@@ -340,9 +340,9 @@ static inline u64 ath5k_extend_tsf(struct ath5k_hw *ah, u32 rstamp)
 }
 
 /* Interrupt handling */
-static int      ath5k_init(struct ath5k_softc *sc);
+static int      ath5k_init(struct ath5k_softc *sc, bool is_resume);
 static int      ath5k_stop_locked(struct ath5k_softc *sc);
-static int      ath5k_stop_hw(struct ath5k_softc *sc);
+static int      ath5k_stop_hw(struct ath5k_softc *sc, bool is_suspend);
 static irqreturn_t ath5k_intr(int irq, void *dev_id);
 static void     ath5k_tasklet_reset(unsigned long data);
 
@@ -646,7 +646,7 @@ ath5k_pci_suspend(struct pci_dev *pdev, pm_message_t state)
 
         ath5k_led_off(sc);
 
-        ath5k_stop_hw(sc);
+        ath5k_stop_hw(sc, true);
 
         free_irq(pdev->irq, sc);
         pci_save_state(pdev);
@@ -683,7 +683,7 @@ ath5k_pci_resume(struct pci_dev *pdev)
                 goto err_no_irq;
         }
 
-        err = ath5k_init(sc);
+        err = ath5k_init(sc, true);
         if (err)
                 goto err_irq;
         ath5k_led_enable(sc);
@@ -2200,12 +2200,17 @@ ath5k_beacon_config(struct ath5k_softc *sc)
 \********************/
 
 static int
-ath5k_init(struct ath5k_softc *sc)
+ath5k_init(struct ath5k_softc *sc, bool is_resume)
 {
         int ret;
 
         mutex_lock(&sc->lock);
 
+        if (is_resume && !test_bit(ATH_STAT_STARTED, sc->status))
+                goto out_ok;
+
+        __clear_bit(ATH_STAT_STARTED, sc->status);
+
         ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "mode %d\n", sc->opmode);
 
         /*
@@ -2230,12 +2235,15 @@ ath5k_init(struct ath5k_softc *sc)
         if (ret)
                 goto done;
 
+        __set_bit(ATH_STAT_STARTED, sc->status);
+
         /* Set ack to be sent at low bit-rates */
         ath5k_hw_set_ack_bitrate_high(sc->ah, false);
 
         mod_timer(&sc->calib_tim, round_jiffies(jiffies +
                         msecs_to_jiffies(ath5k_calinterval * 1000)));
 
+out_ok:
         ret = 0;
 done:
         mmiowb();
@@ -2290,7 +2298,7 @@ ath5k_stop_locked(struct ath5k_softc *sc)
  * stop is preempted).
  */
 static int
-ath5k_stop_hw(struct ath5k_softc *sc)
+ath5k_stop_hw(struct ath5k_softc *sc, bool is_suspend)
 {
         int ret;
 
@@ -2321,6 +2329,9 @@ ath5k_stop_hw(struct ath5k_softc *sc)
                 }
         }
         ath5k_txbuf_free(sc, sc->bbuf);
+        if (!is_suspend)
+                __clear_bit(ATH_STAT_STARTED, sc->status);
+
         mmiowb();
         mutex_unlock(&sc->lock);
 
@@ -2718,12 +2729,12 @@ ath5k_reset_wake(struct ath5k_softc *sc)
 
 static int ath5k_start(struct ieee80211_hw *hw)
 {
-        return ath5k_init(hw->priv);
+        return ath5k_init(hw->priv, false);
 }
 
 static void ath5k_stop(struct ieee80211_hw *hw)
 {
-        ath5k_stop_hw(hw->priv);
+        ath5k_stop_hw(hw->priv, false);
 }
 
 static int ath5k_add_interface(struct ieee80211_hw *hw,
diff --git a/drivers/net/wireless/ath5k/base.h b/drivers/net/wireless/ath5k/base.h
index 9d0b728928e3..06d1054ca94b 100644
--- a/drivers/net/wireless/ath5k/base.h
+++ b/drivers/net/wireless/ath5k/base.h
@@ -128,11 +128,12 @@ struct ath5k_softc {
         size_t                  desc_len;       /* size of TX/RX descriptors */
         u16                     cachelsz;       /* cache line size */
 
-        DECLARE_BITMAP(status, 4);
+        DECLARE_BITMAP(status, 5);
 #define ATH_STAT_INVALID        0               /* disable hardware accesses */
 #define ATH_STAT_MRRETRY        1               /* multi-rate retry support */
 #define ATH_STAT_PROMISC        2
 #define ATH_STAT_LEDSOFT        3               /* enable LED gpio status */
+#define ATH_STAT_STARTED        4               /* opened & irqs enabled */
 
         unsigned int            filter_flags;   /* HW flags, AR5K_RX_FILTER_* */
         unsigned int            curmode;        /* current phy mode */