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| author | Brian Norris <briannorris@chromium.org> | 2016-10-04 11:12:09 -0700 |
|---|---|---|
| committer | Daniel Lezcano <daniel.lezcano@linaro.org> | 2016-11-21 11:05:36 +0100 |
| commit | d8ec7595a013237f82d965dcf981571aeb41855b (patch) | |
| tree | 098c25d78acbd3aa0f22a06c131fef47b674b692 /drivers/clocksource | |
| parent | baa73d9e478ff32d62f3f9422822b59dd9a95a21 (diff) | |
| download | linux-d8ec7595a013237f82d965dcf981571aeb41855b.tar.gz linux-d8ec7595a013237f82d965dcf981571aeb41855b.tar.bz2 linux-d8ec7595a013237f82d965dcf981571aeb41855b.zip | |
clocksource/drivers/arm_arch_timer: Don't assume clock runs in suspend
The ARM specifies that the system counter "must be implemented in an
always-on power domain," and so we try to use the counter as a source of
timekeeping across suspend/resume. Unfortunately, some SoCs (e.g.,
Rockchip's RK3399) do not keep the counter ticking properly when
switched from their high-power clock to the lower-power clock used in
system suspend. Support this quirk by adding a new device tree property.
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/arm_arch_timer.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 73c487da6d2a..a2503db7e533 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -81,6 +81,7 @@ static struct clock_event_device __percpu *arch_timer_evt; static enum ppi_nr arch_timer_uses_ppi = VIRT_PPI; static bool arch_timer_c3stop; static bool arch_timer_mem_use_virtual; +static bool arch_counter_suspend_stop; static bool evtstrm_enable = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM); @@ -576,7 +577,7 @@ static struct clocksource clocksource_counter = { .rating = 400, .read = arch_counter_read, .mask = CLOCKSOURCE_MASK(56), - .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; static struct cyclecounter cyclecounter = { @@ -616,6 +617,8 @@ static void __init arch_counter_register(unsigned type) arch_timer_read_counter = arch_counter_get_cntvct_mem; } + if (!arch_counter_suspend_stop) + clocksource_counter.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP; start_count = arch_timer_read_counter(); clocksource_register_hz(&clocksource_counter, arch_timer_rate); cyclecounter.mult = clocksource_counter.mult; @@ -907,6 +910,10 @@ static int __init arch_timer_of_init(struct device_node *np) of_property_read_bool(np, "arm,cpu-registers-not-fw-configured")) arch_timer_uses_ppi = PHYS_SECURE_PPI; + /* On some systems, the counter stops ticking when in suspend. */ + arch_counter_suspend_stop = of_property_read_bool(np, + "arm,no-tick-in-suspend"); + return arch_timer_init(); } CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init); |