CBUS: Do not BUG_ON in retu-headset in case of spurious release event

There is a small chance that retu_headset_detect_timer can run twice
and pressed flag being zero in second run. Do nothing in that case instead
of throwing BUG_ON.

Double run can happen under very busy system assuming following scenario

1. Hook interrupt (run in softirq context, pressed flag = 1)
2. First retu_headset_enable_timer call
3. Busy system, retu raises an interrupt but cannot run hook interrupt for
   300-350 ms
4. Second hook interrupt
5. First retu_headset_detect_timer call (pressed flag = 0)
6. Second retu_headset_enable_timer
7. Second retu_headset_detect_timer
   -> pressed flag == 0 => BUG_ON

Patch also removes two debug messages since they are not needed very much
and removal cleans up code a bit.

Signed-off-by: Jarkko Nikula <jarkko.nikula@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/drivers/cbus/retu-headset.c b/drivers/cbus/retu-headset.c
index ed2e59b2ff5de385712edbcb691d2a258f4bb544..3161658ea1fab31cb3224160f0b34b57c73b9057 100644 (file)
--- a/drivers/cbus/retu-headset.c
+++ b/drivers/cbus/retu-headset.c
@@ -180,7 +180,6 @@ static void retu_headset_hook_interrupt(unsigned long arg)
 {
        struct retu_headset *hs = (struct retu_headset *) arg;
        unsigned long flags;
-       int was_pressed = 0;
 
        retu_ack_irq(RETU_INT_HOOK);
        spin_lock_irqsave(&hs->lock, flags);
@@ -188,11 +187,8 @@ static void retu_headset_hook_interrupt(unsigned long arg)
                /* Headset button was just pressed down. */
                hs->pressed = 1;
                input_report_key(hs->idev, RETU_HEADSET_KEY, 1);
-               was_pressed = 1;
        }
        spin_unlock_irqrestore(&hs->lock, flags);
-       if (was_pressed)
-               dev_info(&hs->pdev->dev, "button pressed\n");
        retu_set_clear_reg_bits(RETU_REG_CC1, 0, (1 << 10) | (1 << 8));
        mod_timer(&hs->enable_timer, jiffies + msecs_to_jiffies(50));
 }
@@ -211,11 +207,11 @@ static void retu_headset_detect_timer(unsigned long arg)
        unsigned long flags;
 
        spin_lock_irqsave(&hs->lock, flags);
-       BUG_ON(!hs->pressed);
-       input_report_key(hs->idev, RETU_HEADSET_KEY, 0);
-       hs->pressed = 0;
+       if (hs->pressed) {
+               hs->pressed = 0;
+               input_report_key(hs->idev, RETU_HEADSET_KEY, 0);
+       }
        spin_unlock_irqrestore(&hs->lock, flags);
-       dev_info(&hs->pdev->dev, "button released\n");
 }
 
 static int __init retu_headset_probe(struct platform_device *pdev)