linux-toradex.git/drivers/clocksource/cs5535-clockevt.c, branch v4.9.131

clockevents/drivers/cs5535: Improve resilience to spurious interrupts

2017-10-27T08:38:08+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

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

cs5535-clockevt: Free timer in IRQ setup error path

2010-03-12T21:52:00+00:00

Due to a hardware limitation cs5535_mfgpt_free_timer() cannot actually
release the timer hardware, but it will at least free the now unreferenced
struct associated with it so calling it is the cleaner thing to do.

Signed-off-by: Jens Rottmann 
Acked-by: Andres Salomon 
Cc: Jordan Crouse 
Cc: Ingo Molnar 
Cc: john stultz 
Signed-off-by: Andrew Morton 
Signed-off-by: Thomas Gleixner

geode-mfgpt: restore previous behavior for selecting IRQ

2010-02-23T03:50:34+00:00

geode-mfgpt: restore previous behavior for selecting IRQ

The MFGPT IRQ used to be, in order of decreasing priority,
 * IRQ supplied by the user as a boot-time parameter,
 * IRQ previously set by the BIOS or another driver,
 * default IRQ given at compile time.

Return to this behavior, which got broken when splitting the
MFGPT/clocksource driver for 2.6.33-rc1.

Signed-off-by: Jens Rottmann 
Acked-by: Andres Salomon 
Cc: Jordan Crouse 
Cc: Ingo Molnar 
Cc: john stultz 
Acked-by: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds