lwn.git/drivers/clocksource/cs5535-clockevt.c, branch docs-mw

clocksource/drivers/timer-cs5535: Rename the file for consistency

2019-02-23T11:13:45+00:00

For the sake of consistency, let's rename the file to a name similar to other file names in this directory. Signed-off-by: Daniel Lezcano

clockevents/drivers/cs5535: Improve resilience to spurious interrupts

2017-10-20T11:41:52+00:00

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 Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20171020093103.3317F6004D@linux.fjfi.cvut.cz

Annotate hardware config module parameters in drivers/clocksource/

2017-04-20T11:02:32+00:00

When the kernel is running in secure boot mode, we lock down the kernel to prevent userspace from modifying the running kernel image. Whilst this includes prohibiting access to things like /dev/mem, it must also prevent access by means of configuring driver modules in such a way as to cause a device to access or modify the kernel image. To this end, annotate module_param* statements that refer to hardware configuration and indicate for future reference what type of parameter they specify. The parameter parser in the core sees this information and can skip such parameters with an error message if the kernel is locked down. The module initialisation then runs as normal, but just sees whatever the default values for those parameters is. Note that we do still need to do the module initialisation because some drivers have viable defaults set in case parameters aren't specified and some drivers support automatic configuration (e.g. PNP or PCI) in addition to manually coded parameters. This patch annotates drivers in drivers/clocksource/. [Note: With regard to cs5535-clockevt.c, Thomas Gleixner asked whether the timer_irq parameter is required for the driver to work on anything other than arbitrary hardware which has it mapped to 0. Jens Rottmann replied that the parameter defaults to 0, which means: 1. autodetect (=keep IRQ BIOS has set up) 2. if that fails use CONFIG_CS5535_MFGPT_DEFAULT_IRQ (see drivers/misc/cs5535-mfgpt.c: cs5535_mfgpt_set_irq()) Jens further noted that there may not be any systems that have CS5535/36 devices that support EFI and secure boot.] Suggested-by: Alan Cox Signed-off-by: David Howells cc: Daniel Lezcano cc: Thomas Gleixner cc: Jens Rottmann cc: linux-kernel@vger.kernel.org

clockevents/drivers/cs5535: Migrate to new 'set-state' interface

2015-08-06T10:16:42+00:00

Migrate cs5535 driver to the new 'set-state' interface provided by the 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. Acked-by: Daniel Lezcano Cc: Andres Salomon Signed-off-by: Viresh Kumar Signed-off-by: Daniel Lezcano

clocksource: misc drivers: Remove deprecated IRQF_DISABLED

2013-12-11T10:40:27+00:00

This patch removes the use of the IRQF_DISABLED flag It's a NOOP since 2.6.35 and it will be removed one day. [dlezcano] : slightly changed the changelog Signed-off-by: Michael Opdenacker Signed-off-by: Daniel Lezcano

clocksource: use clockevents_config_and_register() where possible

2013-01-14T18:12:42+00:00

The clockevent core is able to figure out the best mult and shift, calculate min_delta_ns and max_delta_ns, with the necessary info passed into clockevents_config_and_register(). Use this combined configure and register function where possible to make the codes less error prone and gain some positive diff stat. Signed-off-by: Shawn Guo Cc: Andres Salomon Cc: Nicolas Ferre Acked-by: Maxime Ripard Acked-by: Arnd Bergmann Reviewed-by: Thomas Gleixner Signed-off-by: Olof Johansson

cs5535-clockevt: typo, it's MFGPT, not MFPGT

2012-08-21T23:45:02+00:00

Signed-off-by: Jens Rottmann Cc: Thomas Gleixner Cc: John Stultz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cs5535-clockevt: Allow the MFGPT IRQ to be shared

2012-03-06T13:17:45+00:00

Shared timer IRQs are not a good solution, however the Geode platform has no APIC, IRQs are a scarce resource and there is no technical reason to forbid it rightaway. Increased latencies and overhead due to sharing are still better than a driver refusing to load. Signed-off-by: Jens Rottmann Acked-by: Andres Salomon Cc: John Stultz Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner

cs5535-clockevt: Don't ignore MFGPT on SMP-capable kernels

2012-03-06T13:17:44+00:00

On SMP-capable kernels (e.g. generic distro kernel) the cs5535-clockevt driver loads but is not actually used. Setting cpumask to cpu_all_mask works for UP-only kernels, but if compiled for SMP - though still running on the same UP hardware - kernel/time/tick-common.c:tick_check_new_device() reads this as "non-cpu-local" and silently ignores the device. If we leave cpumask unset clockevents_register_device() will initialize it and the cs5535-clockevt driver will be used no matter how the kernel was compiled. Should anyone ever manage to stick a CS553x in an SMP system (is this even possible?) then a warning will be printed. This is fine as the cs5535-clockevt driver was never written/tested for SMP. If bisecting led you here this patch may have exposed a pre-existing MFGPT problem. Configure for UP-only and re-check. Signed-off-by: Jens Rottmann Acked-by: Andres Salomon Cc: John Stultz Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner

Andres has moved

2010-07-20T23:25:41+00:00

My Collabora address is no longer enabled - update the MODULE_AUTHOR fields of drivers to my current email address. Signed-off-by: Andres Salomon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds