rt-patches/0324-clockevents-drivers-timer-atmel-pit-fix-double-free_.patch

   1 From 94d8be554c4ea0a28486be59e2eaae937c4403bb Mon Sep 17 00:00:00 2001
   2 From: Alexandre Belloni <alexandre.belloni@free-electrons.com>
   3 Date: Thu, 17 Mar 2016 21:09:43 +0100
   4 Subject: [PATCH 324/366] clockevents/drivers/timer-atmel-pit: fix double
   5  free_irq
   6
   7 clockevents_exchange_device() changes the state from detached to shutdown
   8 and so at that point the IRQ has not yet been requested.
   9
  10 Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
  11 Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
  12 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
  13 ---
  14  drivers/clocksource/timer-atmel-pit.c | 8 +++++++-
  15  1 file changed, 7 insertions(+), 1 deletion(-)
  16
  17 diff --git a/drivers/clocksource/timer-atmel-pit.c b/drivers/clocksource/timer-atmel-pit.c
  18 index a7abdb6..7a40f7e 100644
  19 --- a/drivers/clocksource/timer-atmel-pit.c
  20 +++ b/drivers/clocksource/timer-atmel-pit.c
  21 @@ -46,6 +46,7 @@ struct pit_data {
  22         u32             cycle;
  23         u32             cnt;
  24         unsigned int    irq;
  25 +       bool            irq_requested;
  26         struct clk      *mck;
  27  };
  28
  29 @@ -96,7 +97,10 @@ static int pit_clkevt_shutdown(struct clock_event_device *dev)
  30
  31         /* disable irq, leaving the clocksource active */
  32         pit_write(data->base, AT91_PIT_MR, (data->cycle - 1) | AT91_PIT_PITEN);
  33 -       free_irq(data->irq, data);
  34 +       if (data->irq_requested) {
  35 +               free_irq(data->irq, data);
  36 +               data->irq_requested = false;
  37 +       }
  38         return 0;
  39  }
  40
  41 @@ -115,6 +119,8 @@ static int pit_clkevt_set_periodic(struct clock_event_device *dev)
  42         if (ret)
  43                 panic(pr_fmt("Unable to setup IRQ\n"));
  44
  45 +       data->irq_requested = true;
  46 +
  47         /* update clocksource counter */
  48         data->cnt += data->cycle * PIT_PICNT(pit_read(data->base, AT91_PIT_PIVR));
  49         pit_write(data->base, AT91_PIT_MR,
  50 --
  51 1.9.1
  52