[PATCHv3] wlcore: clean-up clearing of WL1271_FLAG_IRQ_RUNNING

[Tony Lindgren]

We set WL1271_FLAG_IRQ_RUNNING in the beginning of wlcore_irq(), but clear
it before interrupt handling is done in wlcore_irq_locked().

Let's move the clearing to the end of wlcore_irq() where it gets set,
and remove the old comments about hardirq. That's no longer the case as
we're using request_threaded_irq().

Note that the WL1271_FLAG_IRQ_RUNNING should never race between the
interrupt handler and wlcore_runtime_resume() as because of autosuspend
timeout we cannot enter idle between wlcore_irq_locked() and the end of
wlcore_irq().

Cc: Anders Roxell <anders.rox...@linaro.org>
Cc: Eyal Reizer <ey...@ti.com>
Cc: Guy Mishol <g...@ti.com>
Cc: John Stultz <john.stu...@linaro.org>
Cc: Ulf Hansson <ulf.hans...@linaro.org>
Signed-off-by: Tony Lindgren <t...@atomide.com>

Changes since v2:

- Downgraded to clean-up from a fix as the race should never happen

Changes since v1:

- Add locking around clear_bit like we do elsewhere in the driver

---
 drivers/net/wireless/ti/wlcore/main.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/ti/wlcore/main.c 
b/drivers/net/wireless/ti/wlcore/main.c
--- a/drivers/net/wireless/ti/wlcore/main.c
+++ b/drivers/net/wireless/ti/wlcore/main.c
@@ -544,11 +544,6 @@ static int wlcore_irq_locked(struct wl1271 *wl)
        }
 
        while (!done && loopcount--) {
-               /*
-                * In order to avoid a race with the hardirq, clear the flag
-                * before acknowledging the chip.
-                */
-               clear_bit(WL1271_FLAG_IRQ_RUNNING, &wl->flags);
                smp_mb__after_atomic();
 
                ret = wlcore_fw_status(wl, wl->fw_status);
@@ -668,7 +663,7 @@ static irqreturn_t wlcore_irq(int irq, void *cookie)
                disable_irq_nosync(wl->irq);
                pm_wakeup_event(wl->dev, 0);
                spin_unlock_irqrestore(&wl->wl_lock, flags);
-               return IRQ_HANDLED;
+               goto out_handled;
        }
        spin_unlock_irqrestore(&wl->wl_lock, flags);
 
@@ -692,6 +687,11 @@ static irqreturn_t wlcore_irq(int irq, void *cookie)
 
        mutex_unlock(&wl->mutex);
 
+out_handled:
+       spin_lock_irqsave(&wl->wl_lock, flags);
+       clear_bit(WL1271_FLAG_IRQ_RUNNING, &wl->flags);
+       spin_unlock_irqrestore(&wl->wl_lock, flags);
+
        return IRQ_HANDLED;
 }
 
-- 
2.23.0