The bootloader (U-boot) sometimes uses this timer for various delays.
It uses it as a ongoing counter, and does comparisons on the current
counter value. The timer counter is never stopped.
In some cases when the user interacts with the bootloader, or lets
it idle for some time before loading Linux, the timer may expire,
and an interrupt will be pending. This results in an unexpected
interrupt when the timer interrupt is enabled by the kernel, at
which point the event_handler isn't set yet. This results in a NULL
pointer dereference exception, panic, and no way to reboot.
Clear any pending interrupts after we stop the timer in the probe
function to avoid this.
Cc: stable@vger.kernel.org
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
All the clocksource drivers's init function are now converted to return
an error code. CLOCKSOURCE_OF_DECLARE is no longer used as well as the
clksrc-of table.
Let's convert back the names:
- CLOCKSOURCE_OF_DECLARE_RET => CLOCKSOURCE_OF_DECLARE
- clksrc-of-ret => clksrc-of
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
For exynos_mct and samsung_pwm_timer:
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
For arch/arc:
Acked-by: Vineet Gupta <vgupta@synopsys.com>
For mediatek driver:
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
For the Rockchip-part
Acked-by: Heiko Stuebner <heiko@sntech.de>
For STi :
Acked-by: Patrice Chotard <patrice.chotard@st.com>
For the mps2-timer.c and versatile.c changes:
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
For the OXNAS part :
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
For LPC32xx driver:
Acked-by: Sylvain Lemieux <slemieux.tyco@gmail.com>
For Broadcom Kona timer change:
Acked-by: Ray Jui <ray.jui@broadcom.com>
For Sun4i and Sun5i:
Acked-by: Chen-Yu Tsai <wens@csie.org>
For Meson6:
Acked-by: Carlo Caione <carlo@caione.org>
For Keystone:
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
For NPS:
Acked-by: Noam Camus <noamca@mellanox.com>
For bcm2835:
Acked-by: Eric Anholt <eric@anholt.net>
The init functions do not return any error. They behave as the following:
- panic, thus leading to a kernel crash while another timer may work and
make the system boot up correctly
or
- print an error and let the caller unaware if the state of the system
Change that by converting the init functions to return an error conforming
to the CLOCKSOURCE_OF_RET prototype.
Proper error handling (rollback, errno value) will be changed later case
by case, thus this change just return back an error or success in the init
function.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Migrate sun4i driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.
This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
The interrupts were activated and the handler registered before the clockevent
was registered in the probe function.
The interrupt handler, however, was making the assumption that the clockevent
device was registered.
That could cause a null pointer dereference if the timer interrupt was firing
during this narrow window.
Fix that by moving the clockevent registration before the interrupt is enabled.
Reported-by: Roman Byshko <rbyshko@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The Allwinner A10 compatibles were following a slightly different compatible
patterns than the rest of the SoCs for historical reasons. Add compatibles
matching the other pattern to the timer driver for consistency, and keep the
older one for backward compatibility.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Pull clocksource/clockevent updates from Daniel Lezcano:
* Axel Lin removed an unused structure defining the ids for the
bcm kona driver.
* Ezequiel Garcia enabled the timer divider only when the 25MHz
timer is not used for the armada 370 XP.
* Jingoo Han removed a pointless platform data initialization for
the sh_mtu and sh_mtu2.
* Laurent Pinchart added the clk_prepare/clk_unprepare for sh_cmt.
* Linus Walleij added a useful warning in clk_of when no clocks
are found while the old behavior was to silently hang at boot time.
* Maxime Ripard added the high speed timer drivers for the
Allwinner SoCs (A10, A13, A20). He increased the rating, shared the
irq across all available cpus and fixed the clockevent's irq
initialization for the sun4i.
* Michael Opdenacker removed the usage of the IRQF_DISABLED for the
all the timers driver located in drivers/clocksource.
* Stephen Boyd switched to sched_clock_register for the
arm_global_timer, cadence_ttc, sun4i and orion timers.
Conflicts:
drivers/clocksource/clksrc-of.c
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The 32 bit sched_clock interface now supports 64 bits. Upgrade to
the 64 bit function to allow us to remove the 32 bit registration
interface. While we're here, mark the sched_clock function as
notrace to prevent ftrace recursion crashes.
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
We want to keep this driver as the default provider of the clock events
and source, yet some other driver might fit in the "desired" category of
ratings. Hence, we need to increase a bit the rating so that we can have
more flexibility in the ratings we choose.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The interrupt for the timer is a shared processor interrupt, so any CPU
found in the system can handle it. Switch to our cpumask to
cpu_possible_mask instead of cpumask_of(0).
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
The clock event structure irq field was not filled previously to the
interrupt we're using.
This was resulting in the timer not being used at all when using a
configuration with SMP enabled on a system with several CPUs, and with
the cpumask set to the cpu_possible_mask.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
The sun4i timer can still be ticking when we enable the interrupt.
If another timer is actually used (A7 architected timer, for example),
odds are that the interrupt will eventually fire with the event_handler
pointer being NULL.
The obvious fix it to stop the timer before registering the interrupt.
Observed and tested on sun7i (cubietruck).
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
IRQF_DISABLED is a no-op nowadays, so we can safely remove it.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
We need to wait for at least 2 clock cycles whenever we reprogram our
clockevent timer. Report that the minimum number of ticks we can handle
is 3 ticks, and remove 3 ticks to the interval programmed to reflect
this.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The interval was firing at was set up at probe time, and only changed in
the set_next_event, and never changed back, which is not really what is
expected.
When enabling the periodic mode, now set an interval to tick every
jiffy.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The current bring-up code for the timer was overly complicated. The only
thing we need is actually which clock we want to use as source and
that's pretty much all. Let's keep it that way.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The prescaler is only used when using the internal low frequency
oscillator (at 32kHz). Since we're using the higher frequency oscillator
at 24MHz, we can just remove it.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The set_next_event and set_mode callbacks share a lot of common code we
can easily factor to avoid duplication and mistakes.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The next_event logic was setting the next interval to fire in the
current timer value instead of the interval value register, which is
obviously wrong.
Plus, the logic to set the actual value was wrong as well: the interval
register can only be modified when the timer is disabled, and then
enable it back, otherwise, it'll have no effect. Fix this logic as well
since that code couldn't possibly work.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Even if in our case, this clock was non-gatable, used as a parent clock
for several IPs, it still is a good idea to enable it.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Use the second timer found on the Allwinner SoCs as a clock source and
sched clock, that were both not used yet on these platforms.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The name AUTORELOAD was actually pretty bad since it doesn't make the
register reload the previous interval when it expires, but setting this
value pushes the new programmed interval to the internal timer counter.
Rename it to RELOAD instead.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The macros were not using parenthesis to escape the arguments passed to
them. It is pretty unsafe, so add those parenthesis.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
During the introduction of the Allwinner SoC platforms, sunxi was
initially meant as a generic name for all the variants of the Allwinner
SoC.
It was ok at the time of the support of only the A10 and A13 that
looks pretty much the same, but it's beginning to be troublesome with
the future addition of the Allwinner A31 (sun6i) that is quite
different, and would introduce some weird logic, where sunxi would
actually mean in some case sun4i and sun5i but without sun6i...
Moreover, it makes the compatible strings naming scheme not consistent
with other architectures, where usually for this kind of compability, we
just use the oldest SoC name that has this IP, so let's do just this.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
