Merge tag 'omap-for-v3.13/quirk-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into next/dt

From Tony Lindgren:
Changes needed to prepare for making omap3 device tree only:

- Always build in board-generic, and add pdata quirks and auxdata
  support for it so we have all the pdata related quirks
  in the same place.

- Merge of the drivers/pinctrl changes that are needed for PM
  to continue working on omap3 and also needed for other omaps
  eventually. The three pinctrl related patches have been acked
  by Linus Walleij and are pulled into both the pinctrl tree
  and this branch.

- Few defconfig related changes for drivers needed.

* tag 'omap-for-v3.13/quirk-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: (523 commits)
  ARM: configs: omap2plus_defconfig: enable dwc3 and dependencies
  ARM: OMAP2+: Add WLAN modules and of_serial to omap2plus_defconfig
  ARM: OMAP2+: Run make savedefconfig on omap2plus_defconfig to shrink it
  ARM: OMAP2+: Add minimal 8250 support for GPMC
  ARM: OMAP2+: Use pdata quirks for wl12xx for omap3 evm and zoom3
  ARM: OMAP: Move DT wake-up event handling over to use pinctrl-single-omap
  ARM: OMAP2+: Add support for auxdata
  pinctrl: single: Add support for auxdata
  pinctrl: single: Add support for wake-up interrupts
  pinctrl: single: Prepare for supporting SoC specific features
  ARM: OMAP2+: igep0020: use display init from dss-common
  ARM: OMAP2+: pdata-quirks: add legacy display init for IGEPv2 board
  +Linux 3.12-rc4

Signed-off-by: Kevin Hilman <khilman@linaro.org>

1 files changed, 55 insertions, 5 deletions

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 51c4f34d258e..4431610f049a 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -486,7 +486,52 @@ static struct smp_hotplug_thread watchdog_threads = {
         .unpark                 = watchdog_enable,
 };
 
-static int watchdog_enable_all_cpus(void)
+static void restart_watchdog_hrtimer(void *info)
+{
+        struct hrtimer *hrtimer = &__raw_get_cpu_var(watchdog_hrtimer);
+        int ret;
+
+        /*
+         * No need to cancel and restart hrtimer if it is currently executing
+         * because it will reprogram itself with the new period now.
+         * We should never see it unqueued here because we are running per-cpu
+         * with interrupts disabled.
+         */
+        ret = hrtimer_try_to_cancel(hrtimer);
+        if (ret == 1)
+                hrtimer_start(hrtimer, ns_to_ktime(sample_period),
+                                HRTIMER_MODE_REL_PINNED);
+}
+
+static void update_timers(int cpu)
+{
+        struct call_single_data data = {.func = restart_watchdog_hrtimer};
+        /*
+         * Make sure that perf event counter will adopt to a new
+         * sampling period. Updating the sampling period directly would
+         * be much nicer but we do not have an API for that now so
+         * let's use a big hammer.
+         * Hrtimer will adopt the new period on the next tick but this
+         * might be late already so we have to restart the timer as well.
+         */
+        watchdog_nmi_disable(cpu);
+        __smp_call_function_single(cpu, &data, 1);
+        watchdog_nmi_enable(cpu);
+}
+
+static void update_timers_all_cpus(void)
+{
+        int cpu;
+
+        get_online_cpus();
+        preempt_disable();
+        for_each_online_cpu(cpu)
+                update_timers(cpu);
+        preempt_enable();
+        put_online_cpus();
+}
+
+static int watchdog_enable_all_cpus(bool sample_period_changed)
 {
         int err = 0;
 
@@ -496,6 +541,8 @@ static int watchdog_enable_all_cpus(void)
                         pr_err("Failed to create watchdog threads, disabled\n");
                 else
                         watchdog_running = 1;
+        } else if (sample_period_changed) {
+                update_timers_all_cpus();
         }
 
         return err;
@@ -520,13 +567,15 @@ int proc_dowatchdog(struct ctl_table *table, int write,
                     void __user *buffer, size_t *lenp, loff_t *ppos)
 {
         int err, old_thresh, old_enabled;
+        static DEFINE_MUTEX(watchdog_proc_mutex);
 
+        mutex_lock(&watchdog_proc_mutex);
         old_thresh = ACCESS_ONCE(watchdog_thresh);
         old_enabled = ACCESS_ONCE(watchdog_user_enabled);
 
         err = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
         if (err || !write)
-                return err;
+                goto out;
 
         set_sample_period();
         /*
@@ -535,7 +584,7 @@ int proc_dowatchdog(struct ctl_table *table, int write,
          * watchdog_*_all_cpus() function takes care of this.
          */
         if (watchdog_user_enabled && watchdog_thresh)
-                err = watchdog_enable_all_cpus();
+                err = watchdog_enable_all_cpus(old_thresh != watchdog_thresh);
         else
                 watchdog_disable_all_cpus();
 
@@ -544,7 +593,8 @@ int proc_dowatchdog(struct ctl_table *table, int write,
                 watchdog_thresh = old_thresh;
                 watchdog_user_enabled = old_enabled;
         }
-
+out:
+        mutex_unlock(&watchdog_proc_mutex);
         return err;
 }
 #endif /* CONFIG_SYSCTL */
@@ -554,5 +604,5 @@ void __init lockup_detector_init(void)
         set_sample_period();
 
         if (watchdog_user_enabled)
-                watchdog_enable_all_cpus();
+                watchdog_enable_all_cpus(false);
 }