When 32 kHz timer is used the min_delta_ns should be initialized so
that it reflects the timer programming cost. A write to the timer
device will be usually posted, but it takes roughly 3 cycles before
it is effective. If the timer is reprogrammed before that, the CPU
will stall until the previous write completes. This was pointed out by
Richard Woodruff.
Since the lower bound for min_delta_ns is 1000, the change is visible
only with tick rates less than 3 MHz.
Also note that the old value is incorrect for 32 kHz also due to
a rounding error, and it can cause the timer queue to hang (due to
clockevent code trying to program the timer with zero ticks).
Signed-off-by: Aaro Koskinen <Aaro.Koskinen@nokia.com>
Reviewed-by: Richard Woodruff <r-woodruff2@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Impact: change calling convention of existing clock_event APIs
struct clock_event_timer's cpumask field gets changed to take pointer,
as does the ->broadcast function.
Another single-patch change. For safety, we BUG_ON() in
clockevents_register_device() if it's not set.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
This patch optimizes the timer load and start sequence. By combining the
load and start a needless posted wait can be removed from the system timer
execution path.
* Before patch register writes are taking up .078% @ 500MHz during idle.
Address |total |min |max |avr |count|ratio%
old\process\default_idle|7.369s |0.0us|999.902ms|14.477ms|509. |62.661%
ld\Global\cpu_v7_do_idle|4.265s |0.0us|375.786ms|24.374ms|175. |36.270%
(UNKNOWN)|17.503ms|0.us|531.080us|5.119us|3419. |0.148%
r\omap_dm_timer_set_load|8.135ms|0.0us|79.887us|15.065us|540. |0.069% <--
\vmlinux-old\Global\_end|2.023ms|0.0us|4.000us|0.560us|3613. |0.017%
-old\Global\__raw_readsw|1.962ms|0.0us|108.610us|9.167us|214. |0.016%
old\smc91x\smc_interrupt|1.353ms|0.0us|10.212us|2.348us|576. |0.011%
s/namei\__link_path_walk|1.161ms|0.0us|4.310us|0.762us| 1524. |0.009%
\omap_dm_timer_write_reg|1.085ms|0.0us|126.150us|2.153us|504. |0.009% <--
* After patch timer functions do not show up in top listings for long captures.
Signed-off-by: Richard Woodruff <r-woodruff2@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
On OMAP2/3, the gp-timer code can be used for a 32kHz timer simply by
setting the source to be the 32k clock instead of sys_clk.
This patch uses the mach-omap2/timer-gp.c code for 32kHz timer on
OMAP2, moving the logic into mach-omap2/timer-gp.c, and not using
plat-omap/timer32k.c which, for OMAP2, is redundant with the timer-gp
code.
Also, if CONFIG_OMAP_32K_TIMER is enabled, the gptimer-based
clocksource is not used. Instead the default 32k sync counter is used
as the clocksource (see the clocksource in plat-omap/common.c.) This
is important for sleep/suspend so there is a valid counter during
sleep. Note that the suspend/sleep code needs fixing to check for
overflows of this counter.
In addition, the OMAP2/3 details are removed from timer32k.c leaving
that with only OMAP1 specifics. A follow-up patch will move it from
plat-omap common code to mach-omap1.
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Move the xtime write mode seqlock into timer_tick(), so it only
surrounds the call to do_timer().
This avoids a deadlock in update_process_times() ...
hrtimer_get_softirq_time() which tries to get a read mode seqlock
on xtime, thereby preventing booting.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* Convert files to UTF-8.
* Also correct some people's names
(one example is Eißfeldt, which was found in a source file.
Given that the author used an ß at all in a source file
indicates that the real name has in fact a 'ß' and not an 'ss',
which is commonly used as a substitute for 'ß' when limited to
7bit.)
* Correct town names (Goettingen -> Göttingen)
* Update Eberhard Mönkeberg's address (http://lkml.org/lkml/2007/1/8/313)
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Add IRQF_IRQPOLL for each timer interrupt.
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Teach OMAP2 gp timer that HZ isn't always 100.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Fix warning
arch/arm/mach-omap2/timer-gp.c: In function
'omap2_gp_timer_init':
arch/arm/mach-omap2/timer-gp.c:70: warning: implicit
declaration of function 'setup_irq'
Signed-off-by: Dirk Behme <dirk.behme_at_gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Untested, but this should fix up the bulk of the totally mechanical
issues, and should make the actual detail fixing easier.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The irgflags consolidation did conflict with the ARM to generic IRQ
conversion and was not applied for ARM. Fix it up.
Use the new IRQF_ constants and remove the SA_INTERRUPT define
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The dmtimer framework update broke 32 kHz timer as udelay() does not work
before system timer is started (and GPT1 should not be reset).
This also makes the GP timer use GPT1. This requires a fix in clock framework.
Signed-off-by: Timo Teras <timo.teras@solidboot.com>
Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Port dmtimer framework to OMAP2.
Modify the dmtimers API to support setting of PWM configuration and prescaler.
Convert 32 kHz timer and GP timer to use the dmtimer framework.
Signed-off-by: Timo Teras <timo.teras@solidboot.com>
Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This patch fixes OMAP clock framework to use clk_enable/disable
instead of clk_use/unuse as specified in include/linux/clk.h.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Patch from Tony Lindgren
This patch adds support for omap24xx series of processors.
The files live in arch/arm/mach-omap2, and share common
files with omap15xx and omap16xx processors in
arch/arm/plat-omap.
Omap24xx support was originally added for 2.6.9 by TI.
This code was then improved and integrated to share common
code with omap15xx and omap16xx processors by various
omap developers, such as Paul Mundt, Juha Yrjola, Imre Deak,
Tony Lindgren, Richard Woodruff, Nishant Menon, Komal Shah
et al.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
