diff options
| author | Doug Anderson <dianders@chromium.org> | 2014-07-04 23:38:55 +0200 |
|---|---|---|
| committer | Kukjin Kim <kgene.kim@samsung.com> | 2014-07-04 23:38:55 +0200 |
| commit | 89e6a13b88c8bf7ce1011a8a69113f22889f4585 (patch) | |
| tree | 2f04536d0899aed9d030184dda2b2e6104fc3076 /drivers | |
| parent | ARM: dts: fix pwm-cells in pwm node for exynos4 (diff) | |
| download | linux-89e6a13b88c8bf7ce1011a8a69113f22889f4585.tar.xz linux-89e6a13b88c8bf7ce1011a8a69113f22889f4585.zip | |
clocksource: exynos_mct: Fix ftrace
In (93bfb76 clocksource: exynos_mct: register sched_clock callback) we
supported using the MCT as a scheduler clock. We properly marked
exynos4_read_sched_clock() as notrace. However, we then went and
called another function that _wasn't_ notrace. That means if you do:
cd /sys/kernel/debug/tracing/
echo function_graph > current_tracer
You'll get a crash.
Fix this (but still let other readers of the MCT be trace-enabled) by
adding an extra function. It's important to keep other users of MCT
traceable because the MCT is actually quite slow to access and we want
exynos4_frc_read() to show up in ftrace profiles if it's the
bottleneck.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/clocksource/exynos_mct.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c index f71d55f5e6e5..5ce99c07ce8c 100644 --- a/drivers/clocksource/exynos_mct.c +++ b/drivers/clocksource/exynos_mct.c @@ -162,7 +162,7 @@ static void exynos4_mct_frc_start(void) exynos4_mct_write(reg, EXYNOS4_MCT_G_TCON); } -static cycle_t exynos4_frc_read(struct clocksource *cs) +static cycle_t notrace _exynos4_frc_read(void) { unsigned int lo, hi; u32 hi2 = __raw_readl(reg_base + EXYNOS4_MCT_G_CNT_U); @@ -176,6 +176,11 @@ static cycle_t exynos4_frc_read(struct clocksource *cs) return ((cycle_t)hi << 32) | lo; } +static cycle_t exynos4_frc_read(struct clocksource *cs) +{ + return _exynos4_frc_read(); +} + static void exynos4_frc_resume(struct clocksource *cs) { exynos4_mct_frc_start(); @@ -192,7 +197,7 @@ struct clocksource mct_frc = { static u64 notrace exynos4_read_sched_clock(void) { - return exynos4_frc_read(&mct_frc); + return _exynos4_frc_read(); } static void __init exynos4_clocksource_init(void) |