kernel/linux.git/drivers/clocksource, branch v4.4.171

clockevents/drivers/i8253: Add support for PIT shutdown quirk

2018-11-21T08:27:42+00:00

commit 35b69a420bfb56b7b74cb635ea903db05e357bec upstream. Add support for platforms where pit_shutdown() doesn't work because of a quirk in the PIT emulation. On these platforms setting the counter register to zero causes the PIT to start running again, negating the shutdown. Provide a global variable that controls whether the counter register is zero'ed, which platform specific code can override. Signed-off-by: Michael Kelley Signed-off-by: Thomas Gleixner Cc: "gregkh@linuxfoundation.org" Cc: "devel@linuxdriverproject.org" Cc: "daniel.lezcano@linaro.org" Cc: "virtualization@lists.linux-foundation.org" Cc: "jgross@suse.com" Cc: "akataria@vmware.com" Cc: "olaf@aepfle.de" Cc: "apw@canonical.com" Cc: vkuznets Cc: "jasowang@redhat.com" Cc: "marcelo.cerri@canonical.com" Cc: KY Srinivasan Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1541303219-11142-2-git-send-email-mikelley@microsoft.com Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/ti-32k: Add CLOCK_SOURCE_SUSPEND_NONSTOP flag for non-am43 SoCs

2018-10-20T07:52:37+00:00

[ Upstream commit 3b7d96a0dbb6b630878597a1838fc39f808b761b ] The 32k clocksource is NONSTOP for non-am43 SoCs. Hence add the flag for all the other SoCs. Reported-by: Tony Lindgren Signed-off-by: Keerthy Acked-by: Tony Lindgren Signed-off-by: Daniel Lezcano Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/fsl_ftm_timer: Fix error return checking

2018-05-30T05:49:01+00:00

[ Upstream commit f287eb9013ccf199cbfa4eabd80c36fedfc15a73 ] The error checks on freq for a negative error return always fails because freq is unsigned and can never be negative. Fix this by making freq a signed long. Detected with Coccinelle: drivers/clocksource/fsl_ftm_timer.c:287:5-9: WARNING: Unsigned expression compared with zero: freq <= 0 drivers/clocksource/fsl_ftm_timer.c:291:5-9: WARNING: Unsigned expression compared with zero: freq <= 0 Fixes: 2529c3a33079 ("clocksource: Add Freescale FlexTimer Module (FTM) timer support") Signed-off-by: Colin Ian King Signed-off-by: Thomas Gleixner Cc: Daniel Lezcano Cc: kernel-janitors@vger.kernel.org Link: https://lkml.kernel.org/r/20180226113614.3092-1-colin.king@canonical.com Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

clockevents/drivers/cs5535: Improve resilience to spurious interrupts

2017-10-27T08:23:17+00:00

commit eb39a7c0355393c5a8d930f342ad7a6231b552c4 upstream. The interrupt handler mfgpt_tick() is not robust versus spurious interrupts which happen before the clock event device is registered and fully initialized. The reason is that the safe guard against spurious interrupts solely checks for the clockevents shutdown state, but lacks a check for detached state. If the interrupt hits while the device is in detached state it passes the safe guard and dereferences the event handler call back which is NULL. Add the missing state check. Fixes: 8f9327cbb6e8 ("clockevents/drivers/cs5535: Migrate to new 'set-state' interface") Suggested-by: Thomas Gleixner Signed-off-by: David Kozub Signed-off-by: Thomas Gleixner Cc: Daniel Lezcano Link: https://lkml.kernel.org/r/20171020093103.3317F6004D@linux.fjfi.cvut.cz Signed-off-by: Greg Kroah-Hartman

clocksource/exynos_mct: Clear interrupt when cpu is shut down

2017-01-26T07:23:48+00:00

commit bc7c36eedb0c7004aa06c2afc3c5385adada8fa3 upstream. When a CPU goes offline a potentially pending timer interrupt is not cleared. When the CPU comes online again then the pending interrupt is delivered before the per cpu clockevent device is initialized. As a consequence the tick interrupt handler dereferences a NULL pointer. [ 51.251378] Unable to handle kernel NULL pointer dereference at virtual address 00000040 [ 51.289348] task: ee942d00 task.stack: ee960000 [ 51.293861] PC is at tick_periodic+0x38/0xb0 [ 51.298102] LR is at tick_handle_periodic+0x1c/0x90 Clear the pending interrupt in the cpu dying path. Fixes: 56a94f13919c ("clocksource: exynos_mct: Avoid blocking calls in the cpu hotplug notifier") Reported-by: Seung-Woo Kim Signed-off-by: Joonyoung Shim Cc: linux-samsung-soc@vger.kernel.org Cc: cw00.choi@samsung.com Cc: daniel.lezcano@linaro.org Cc: javier@osg.samsung.com Cc: kgene@kernel.org Cc: krzk@kernel.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1484628876-22065-1-git-send-email-jy0922.shim@samsung.com Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/sun4i: Clear interrupts after stopping timer in probe function

2016-09-24T08:07:35+00:00

commit b53e7d000d9e6e9fd2c6eb6b82d2783c67fd599e upstream. 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. Signed-off-by: Chen-Yu Tsai Signed-off-by: Daniel Lezcano Acked-by: Maxime Ripard Signed-off-by: Greg Kroah-Hartman

clockevents/tcb_clksrc: Prevent disabling an already disabled clock

2016-03-03T23:07:15+00:00

commit f02b4b72d12cbae7020a959e2ed0410a464b4cc4 upstream. clockevents_exchange_device is calling clockevents_shutdown() on the new clockenvents device but it may have never been enabled in the first place. This results in the tcb clock being disabled without being enabled first: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:680 clk_disable+0x28/0x34() Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 4.4.0+ #6 Hardware name: Atmel AT91SAM9 [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (warn_slowpath_common+0x78/0xa0) [] (warn_slowpath_common) from [] (warn_slowpath_null+0x18/0x20) [] (warn_slowpath_null) from [] (clk_disable+0x28/0x34) [] (clk_disable) from [] (tc_shutdown+0x38/0x4c) [] (tc_shutdown) from [] (clockevents_switch_state+0x38/0x6c) [] (clockevents_switch_state) from [] (clockevents_shutdown+0x10/0x24) [] (clockevents_shutdown) from [] (tick_check_new_device+0x84/0xac) [] (tick_check_new_device) from [] (clockevents_register_device+0x7c/0x108) [] (clockevents_register_device) from [] (tcb_clksrc_init+0x390/0x3e8) [] (tcb_clksrc_init) from [] (do_one_initcall+0x114/0x1d4) [] (do_one_initcall) from [] (kernel_init_freeable+0xfc/0x1b8) [] (kernel_init_freeable) from [] (kernel_init+0x8/0xe0) [] (kernel_init) from [] (ret_from_fork+0x14/0x24) ---[ end trace 0000000000000001 ]--- Check what state we were in before trying to disable the clock. Fixes: cf4541c101ea ("clockevents/drivers/tcb_clksrc: Migrate to new 'set-state' interface") Signed-off-by: Alexandre Belloni Cc: Nicolas Ferre Cc: Boris Brezillon Cc: linux-arm-kernel@lists.infradead.org Cc: Daniel Lezcano Link: http://lkml.kernel.org/r/1452854061-30370-1-git-send-email-alexandre.belloni@free-electrons.com Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/vt8500: Increase the minimum delta

2016-03-03T23:07:11+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: Mmio: remove artificial 32bit limitation

2015-12-10T18:37:18+00:00

The EP93xx is registering a clocksource of 40 bits with clocksource_mmio_init() but this is not working because of this artificial limitation. It works fine to lift the uppe limit to 64 bits, and since cycle_t is u64, it should intuitively have been like that from the beginning. Fixes: 000bc17817bf "ARM: ep93xx: switch to GENERIC_CLOCKEVENTS" Reported-by: Alexander Sverdlin Signed-off-by: Linus Walleij Cc: Daniel Lezcano Link: http://lkml.kernel.org/r/1449768101-6879-1-git-send-email-linus.walleij@linaro.org Signed-off-by: Thomas Gleixner

clocksource: Disallow drivers for ARCH_USES_GETTIMEOFFSET

2015-11-16T18:07:08+00:00

We can now select clocksource drivers like ti-32k and CONFIG_OF on ancient machines that still use gettimeoffset, and the combination results in a link error. arch/arm/kernel/built-in.o: In function `time_init': (.init.text+0xc28): undefined reference to `clocksource_probe' The reason for this is that the Makefile is hidden behind CONFIG_ARCH_USES_GETTIMEOFFSET, but the Kconfig file is not, and it has shown up just now because the ti-32k driver was added and can be selected using COMPILE_TEST on all platforms. This patch hides the Kconfig menu in CONFIG_ARCH_USES_GETTIMEOFFSET as well. Fixes: dfedaf105d60 "clocksource: ti-32k: make it depend on GENERIC_CLOCKSOURCE" Signed-off-by: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org Cc: Felipe Balbi Cc: Tony Lindgren Cc: Daniel Lezcano Link: http://lkml.kernel.org/r/7579471.4N90fYPQOK@wuerfel Signed-off-by: Thomas Gleixner