Merge tag 'timers-core-2022-12-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "Updates for timers, timekeeping and drivers:

  Core:

   - The timer_shutdown[_sync]() infrastructure:

     Tearing down timers can be tedious when there are circular
     dependencies to other things which need to be torn down. A prime
     example is timer and workqueue where the timer schedules work and
     the work arms the timer.

     What needs to prevented is that pending work which is drained via
     destroy_workqueue() does not rearm the previously shutdown timer.
     Nothing in that shutdown sequence relies on the timer being
     functional.

     The conclusion was that the semantics of timer_shutdown_sync()
     should be:
	- timer is not enqueued
    	- timer callback is not running
    	- timer cannot be rearmed

     Preventing the rearming of shutdown timers is done by discarding
     rearm attempts silently.

     A warning for the case that a rearm attempt of a shutdown timer is
     detected would not be really helpful because it's entirely unclear
     how it should be acted upon. The only way to address such a case is
     to add 'if (in_shutdown)' conditionals all over the place. This is
     error prone and in most cases of teardown not required all.

   - The real fix for the bluetooth HCI teardown based on
     timer_shutdown_sync().

     A larger scale conversion to timer_shutdown_sync() is work in
     progress.

   - Consolidation of VDSO time namespace helper functions

   - Small fixes for timer and timerqueue

  Drivers:

   - Prevent integer overflow on the XGene-1 TVAL register which causes
     an never ending interrupt storm.

   - The usual set of new device tree bindings

   - Small fixes and improvements all over the place"

* tag 'timers-core-2022-12-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
  dt-bindings: timer: renesas,cmt: Add r8a779g0 CMT support
  dt-bindings: timer: renesas,tmu: Add r8a779g0 support
  clocksource/drivers/arm_arch_timer: Use kstrtobool() instead of strtobool()
  clocksource/drivers/timer-ti-dm: Fix missing clk_disable_unprepare in dmtimer_systimer_init_clock()
  clocksource/drivers/timer-ti-dm: Clear settings on probe and free
  clocksource/drivers/timer-ti-dm: Make timer_get_irq static
  clocksource/drivers/timer-ti-dm: Fix warning for omap_timer_match
  clocksource/drivers/arm_arch_timer: Fix XGene-1 TVAL register math error
  clocksource/drivers/timer-npcm7xx: Enable timer 1 clock before use
  dt-bindings: timer: nuvoton,npcm7xx-timer: Allow specifying all clocks
  dt-bindings: timer: rockchip: Add rockchip,rk3128-timer
  clockevents: Repair kernel-doc for clockevent_delta2ns()
  clocksource/drivers/ingenic-ost: Define pm functions properly in platform_driver struct
  clocksource/drivers/sh_cmt: Access registers according to spec
  vdso/timens: Refactor copy-pasted find_timens_vvar_page() helper into one copy
  Bluetooth: hci_qca: Fix the teardown problem for real
  timers: Update the documentation to reflect on the new timer_shutdown() API
  timers: Provide timer_shutdown[_sync]()
  timers: Add shutdown mechanism to the internal functions
  timers: Split [try_to_]del_timer[_sync]() to prepare for shutdown mode
  ...

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index 8df11016fd51b..ba8be8e1bebd3 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -696,9 +696,15 @@ static int qca_close(struct hci_uart *hu)
 	skb_queue_purge(&qca->tx_wait_q);
 	skb_queue_purge(&qca->txq);
 	skb_queue_purge(&qca->rx_memdump_q);
+	/*
+	 * Shut the timers down so they can't be rearmed when
+	 * destroy_workqueue() drains pending work which in turn might try
+	 * to arm a timer.  After shutdown rearm attempts are silently
+	 * ignored by the timer core code.
+	 */
+	timer_shutdown_sync(&qca->tx_idle_timer);
+	timer_shutdown_sync(&qca->wake_retrans_timer);
 	destroy_workqueue(qca->workqueue);
-	del_timer_sync(&qca->tx_idle_timer);
-	del_timer_sync(&qca->wake_retrans_timer);
 	qca->hu = NULL;
 
 	kfree_skb(qca->rx_skb);