diff options
| author |   Richard Woodruff <r-woodruff2@ti.com> | 2008-07-03 12:24:30 +0300 |
|---|---|---|
| committer |   Tony Lindgren <tony@atomide.com> | 2008-07-03 12:24:30 +0300 |
| commit | 3fddd09e59cf49dc339e2de74d31a76c1f7f172f (patch) | |
| tree | 2c3ebae6e34d0becf0f4e4b9fe11db70c7275a42 /arch/arm/plat-omap | |
| parent | ARM: OMAP: DMTimer: Use posted mode (diff) | |
| download | linux-dev-3fddd09e59cf49dc339e2de74d31a76c1f7f172f.tar.xz linux-dev-3fddd09e59cf49dc339e2de74d31a76c1f7f172f.zip | |
ARM: OMAP: DMTimer: Optimize by adding load and start
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>
Diffstat (limited to 'arch/arm/plat-omap')
| -rw-r--r-- | arch/arm/plat-omap/dmtimer.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c index 822b6bb5c74c..f22506af0e67 100644 --- a/arch/arm/plat-omap/dmtimer.c +++ b/arch/arm/plat-omap/dmtimer.c @@ -546,6 +546,24 @@ void omap_dm_timer_set_load(struct omap_dm_timer *timer, int autoreload, omap_dm_timer_write_reg(timer, OMAP_TIMER_TRIGGER_REG, 0); } +/* Optimized set_load which removes costly spin wait in timer_start */ +void omap_dm_timer_set_load_start(struct omap_dm_timer *timer, int autoreload, + unsigned int load) +{ + u32 l; + + l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG); + if (autoreload) + l |= OMAP_TIMER_CTRL_AR; + else + l &= ~OMAP_TIMER_CTRL_AR; + l |= OMAP_TIMER_CTRL_ST; + + omap_dm_timer_write_reg(timer, OMAP_TIMER_COUNTER_REG, load); + omap_dm_timer_write_reg(timer, OMAP_TIMER_LOAD_REG, load); + omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l); +} + void omap_dm_timer_set_match(struct omap_dm_timer *timer, int enable, unsigned int match) { @@ -560,7 +578,6 @@ void omap_dm_timer_set_match(struct omap_dm_timer *timer, int enable, omap_dm_timer_write_reg(timer, OMAP_TIMER_MATCH_REG, match); } - void omap_dm_timer_set_pwm(struct omap_dm_timer *timer, int def_on, int toggle, int trigger) { |