linux.git/drivers/clocksource, branch v3.10.100

clocksource/drivers/vt8500: Increase the minimum delta

2016-03-03T23:06:20+00:00

commit f9eccf24615672896dc13251410c3f2f33a14f95 upstream.

The vt8500 clocksource driver declares itself as capable to handle the
minimum delay of 4 cycles by passing the value into
clockevents_config_and_register(). The vt8500_timer_set_next_event()
requires the passed cycles value to be at least 16. The impact is that
userspace hangs in nanosleep() calls with small delay intervals.

This problem is reproducible in Linux 4.2 starting from:
c6eb3f70d448 ('hrtimer: Get rid of hrtimer softirq')

From Russell King, more detailed explanation:

"It's a speciality of the StrongARM/PXA hardware. It takes a certain
number of OSCR cycles for the value written to hit the compare registers.
So, if a very small delta is written (eg, the compare register is written
with a value of OSCR + 1), the OSCR will have incremented past this value
before it hits the underlying hardware. The result is, that you end up
waiting a very long time for the OSCR to wrap before the event fires.

So, we introduce a check in set_next_event() to detect this and return
-ETIME if the calculated delta is too small, which causes the generic
clockevents code to retry after adding the min_delta specified in
clockevents_config_and_register() to the current time value.

min_delta must be sufficient that we don't re-trip the -ETIME check - if
we do, we will return -ETIME, forward the next event time, try to set it,
return -ETIME again, and basically lock the system up. So, min_delta
must be larger than the check inside set_next_event(). A factor of two
was chosen to ensure that this situation would never occur.

The PXA code worked on PXA systems for years, and I'd suggest no one
changes this mechanism without access to a wide range of PXA systems,
otherwise they're risking breakage."

Cc: Russell King 
Acked-by: Alexey Charkov 
Signed-off-by: Roman Volkov 
Signed-off-by: Daniel Lezcano 
Signed-off-by: Greg Kroah-Hartman

clocksource: exynos_mct: Fix bitmask regression for exynos4_mct_write

2015-01-30T01:40:56+00:00

commit 8c38d28ba8da98f7102c31d35359b4dbe9d1f329 upstream.

EXYNOS4_MCT_L_MASK is defined as 0xffffff00, so applying this bitmask
produces a number outside the range 0x00 to 0xff, which always results
in execution of the default switch statement.

Obviously this is wrong and git history shows that the bitmask inversion
was incorrectly set during a refactoring of the MCT code.

Fix this by putting the inversion at the correct position again.

Acked-by: Kukjin Kim 
Reported-by: GP Orcullo 
Reviewed-by: Doug Anderson 
Signed-off-by: Tobias Jakobi 
Signed-off-by: Daniel Lezcano 
Signed-off-by: Greg Kroah-Hartman

clocksource: Exynos_mct: Register clock event after request_irq()

2014-06-07T20:25:29+00:00

commit 8db6e5104b77de5d0b7002b95069da0992a34be9 upstream.

After hotplugging CPU1 the first call of interrupt handler for CPU1
oneshot timer was called on CPU0 because it fired before setting IRQ
affinity. Affected are SoCs where Multi Core Timer interrupts are
shared (SPI), e.g. Exynos 4210.

During setup of the MCT timers the clock event device should be
registered after setting the affinity for interrupt. This will prevent
starting the timer too early.

Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: Thomas Gleixner 
Cc: Kyungmin Park 
Cc: Marek Szyprowski 
Cc: Bartlomiej Zolnierkiewicz 
Cc: Tomasz Figa ,
Cc: Daniel Lezcano ,
Cc: Kukjin Kim 
Cc: linux-arm-kernel@lists.infradead.org,
Link: http://lkml.kernel.org/r/20140416143316.299247848@linutronix.de
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

clocksource: em_sti: Set cpu_possible_mask to fix SMP broadcast

2014-01-15T23:28:45+00:00

commit 2199a5574b6d94b9ca26c6345356f45ec60fef8b upstream.

Update the STI driver by setting cpu_possible_mask to make EMEV2
SMP work as expected together with the ARM broadcast timer.

This breakage was introduced by:

f7db706 ARM: 7674/1: smp: Avoid dummy clockevent being preferred over real hardware clock-event

Without this fix SMP operation is broken on EMEV2 since no
broadcast timer interrupts trigger on the secondary CPU cores.

Signed-off-by: Magnus Damm 
Tested-by: Simon Horman 
Reviewed-by: Stephen Boyd 
Signed-off-by: Simon Horman 
Signed-off-by: Daniel Lezcano 
Signed-off-by: Greg Kroah-Hartman

clocksource: arch_timer: use virtual counters

2014-01-09T20:24:26+00:00

commit 0d651e4e65e96989f72236bf83bd4c6e55eb6ce4 upstream.

Switching between reading the virtual or physical counters is
problematic, as some core code wants a view of time before we're fully
set up. Using a function pointer and switching the source after the
first read can make time appear to go backwards, and having a check in
the read function is an unfortunate block on what we want to be a fast
path.

Instead, this patch makes us always use the virtual counters. If we're a
guest, or don't have hyp mode, we'll use the virtual timers, and as such
don't care about CNTVOFF as long as it doesn't change in such a way as
to make time appear to travel backwards. As the guest will use the
virtual timers, a (potential) KVM host must use the physical timers
(which can wake up the host even if they fire while a guest is
executing), and hence a host must have CNTVOFF set to zero so as to have
a consistent view of time between the physical timers and virtual
counters.

Signed-off-by: Mark Rutland 
Acked-by: Catalin Marinas 
Acked-by: Marc Zyngier 
Acked-by: Santosh Shilimkar 
Cc: Rob Herring 
Cc: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

clocksource: dw_apb_timer_of: Fix read_sched_clock

2014-01-09T20:24:24+00:00

commit 85dc6ee1237c8a4a7742e6abab96a20389b7d682 upstream.

The read_sched_clock should return the ~value because the clock is a
countdown implementation. read_sched_clock() should be the same as
 __apbt_read_clocksource().

Signed-off-by: Dinh Nguyen 
Signed-off-by: Daniel Lezcano 
Signed-off-by: Greg Kroah-Hartman

clocksource: dw_apb: Fix error check

2013-07-25T21:07:29+00:00

commit 1a33bd2be705cbb3f57d7223b60baea441039307 upstream.

irq_of_parse_and_map() returns 0 on error, while the code checks for NO_IRQ.
This breaks on platforms that have NO_IRQ != 0.

Signed-off-by: Baruch Siach 
Signed-off-by: Daniel Lezcano 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'multiplatform-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

2013-05-07T18:28:42+00:00

Pull late ARM Exynos multiplatform changes from Arnd Bergmann:
 "These continue the multiplatform support for exynos, adding support
  for building most of the essential drivers (clocksource, clk, irqchip)
  when combined with other platforms.  As a result, it should become
  really easy to add full multiplatform exynos support in 3.11, although
  we don't yet enable it for 3.10.

  The changes were not included in the earlier multiplatform series in
  order to avoid clashes with the other Exynos updates.

  This also includes work from Tomasz Figa to fix the pwm clocksource
  code on Exynos, which is not strictly required for multiplatform, but
  related to the other patches in this set and needed as a bug fix for
  at least one board."

* tag 'multiplatform-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (22 commits)
  ARM: dts: exynops4210: really add universal_c210 dts
  ARM: dts: exynos4210: Add basic dts file for universal_c210 board
  ARM: dts: exynos4: Add node for PWM device
  ARM: SAMSUNG: Do not register legacy timer interrupts on Exynos
  clocksource: samsung_pwm_timer: Work around rounding errors in clockevents core
  clocksource: samsung_pwm_timer: Correct programming of clock events
  clocksource: samsung_pwm_timer: Use proper clockevents max_delta
  clocksource: samsung_pwm_timer: Add support for non-DT platforms
  clocksource: samsung_pwm_timer: Drop unused samsung_pwm struct
  clocksource: samsung_pwm_timer: Keep all driver data in a structure
  clocksource: samsung_pwm_timer: Make PWM spinlock global
  clocksource: samsung_pwm_timer: Let platforms select the driver
  Documentation: Add device tree bindings for Samsung PWM timers
  clocksource: add samsung pwm timer driver
  irqchip: exynos: look up irq using irq_find_mapping
  irqchip: exynos: pass irq_base from platform
  irqchip: exynos: localize irq lookup for ATAGS
  irqchip: exynos: allocate combiner_data dynamically
  irqchip: exynos: pass max combiner number to combiner_init
  ARM: exynos: add missing properties for combiner IRQs
  ...

Merge tag 'cleanup-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

2013-05-07T18:22:14+00:00

Pull ARM SoC late cleanups from Arnd Bergmann:
 "These are cleanups and smaller changes that either depend on earlier
  feature branches or came in late during the development cycle.  We
  normally try to get all cleanups early, so these are the exceptions:

   - A follow-up on the clocksource reworks, hopefully the last time we
     need to merge clocksource subsystem changes through arm-soc.

     A first set of patches was part of the original 3.10 arm-soc
     cleanup series because of interdependencies with timer drivers now
     moved out of arch/arm.

   - Migrating the SPEAr13xx platform away from using auxdata for DMA
     channel descriptions towards using information in device tree,
     based on the earlier SPEAr multiplatform series

   - A few follow-ups on the Atmel SAMA5 support and other changes for
     Atmel at91 based on the larger at91 reworks.

   - Moving the armada irqchip implementation to drivers/irqchip

   - Several OMAP cleanups following up on the larger series already
     merged in 3.10."

* tag 'cleanup-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (50 commits)
  ARM: OMAP4: change the device names in usb_bind_phy
  ARM: OMAP2+: Fix mismerge for timer.c between ff931c82 and da4a686a
  ARM: SPEAr: conditionalize SMP code
  ARM: arch_timer: Silence debug preempt warnings
  ARM: OMAP: remove unused variable
  serial: amba-pl011: fix !CONFIG_DMA_ENGINE case
  ata: arasan: remove the need for platform_data
  ARM: at91/sama5d34ek.dts: remove not needed compatibility string
  ARM: at91: dts: add MCI DMA support
  ARM: at91: dts: add i2c dma support
  ARM: at91: dts: set #dma-cells to the correct value
  ARM: at91: suspend both memory controllers on at91sam9263
  irqchip: armada-370-xp: slightly cleanup irq controller driver
  irqchip: armada-370-xp: move IRQ handler to avoid forward declaration
  irqchip: move IRQ driver for Armada 370/XP
  ARM: mvebu: move L2 cache initialization in init_early()
  devtree: add binding documentation for sp804
  ARM: integrator-cp: convert use CLKSRC_OF for timer init
  ARM: versatile: use OF init for sp804 timer
  ARM: versatile: add versatile dtbs to dtbs target
  ...

Merge branch 'exynos/pwm-clocksource' into late/multiplatform

2013-05-06T21:49:09+00:00

This series from Tomasz Figa restores support for the pwm clocksource
in Exynos, which was broken during the conversion of the platform
to the common clk framework. The clocksource is only used in one
board in the mainline kernel (universal_c210), and this makes it
work for DT based probing as well as restoring the non-DT based
case.

* exynos/pwm-clocksource:
  ARM: dts: exynops4210: really add universal_c210 dts
  ARM: dts: exynos4210: Add basic dts file for universal_c210 board
  ARM: dts: exynos4: Add node for PWM device
  ARM: SAMSUNG: Do not register legacy timer interrupts on Exynos
  clocksource: samsung_pwm_timer: Work around rounding errors in clockevents core
  clocksource: samsung_pwm_timer: Correct programming of clock events
  clocksource: samsung_pwm_timer: Use proper clockevents max_delta
  clocksource: samsung_pwm_timer: Add support for non-DT platforms
  clocksource: samsung_pwm_timer: Drop unused samsung_pwm struct
  clocksource: samsung_pwm_timer: Keep all driver data in a structure
  clocksource: samsung_pwm_timer: Make PWM spinlock global
  clocksource: samsung_pwm_timer: Let platforms select the driver
  Documentation: Add device tree bindings for Samsung PWM timers
  clocksource: add samsung pwm timer driver

Conflicts:
	arch/arm/boot/dts/Makefile
	arch/arm/mach-exynos/common.c
	drivers/clocksource/Kconfig
	drivers/clocksource/Makefile

Signed-off-by: Arnd Bergmann