Commit graph

8 commits

Author SHA1 Message Date
Kevin Hilman
9799aca203 OMAP: omap_device: optionally auto-adjust device activate/deactivate latencies
First, this patch adds new worst-case latency values to the
omap_device_pm_latency struct.  Here the worst-case measured latencies
for the activate and deactivate hooks are stored.

In addition, add an option to auto-adjust the latency values used for
device activate/deactivate.

By setting a new 'OMAP_DEVICE_LATENCY_AUTO_ADJUST' flag in the
omap_device_pm_latency struct, the omap_device layer automatically
adjusts the activate/deactivate latencies to the worst-case measured
values.

Anytime a new worst-case value is found, it is printed to the console.
Here is an example log during boot using UART2 s an example.  After
boot, the OPP is manually changed to the 125MHz OPP:

[...]
Freeing init memory: 128K
omap_device: serial8250.2: new worst case deactivate latency 0: 30517
omap_device: serial8250.2: new worst case activate latency 0: 30517
omap_device: serial8250.2: new worst case activate latency 0: 218139648
omap_device: serial8250.2: new worst case deactivate latency 0: 61035
omap_device: serial8250.2: new worst case activate latency 0: 278076171
omap_device: serial8250.2: new worst case activate latency 0: 298614501
omap_device: serial8250.2: new worst case activate latency 0: 327331542

/ # echo 125000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed

omap_device: serial8250.2: new worst case deactivate latency 0: 91552

Motivation: this can be used as a technique to automatically determine
the worst case latency values.  The current method of printing a
warning on every violation is too noisy to actually interact the
console in order to set low OPP to discover latencies.

Another motivation for this patch is that the activate/deactivate
latenices can vary depending on the idlemode of the device.  While
working on the UARTs, I noticed that when using no-idle, the activate
latencies were as high as several hundred msecs as shown above.  When
the UARTs are in smart-idle, the max latency is well under 100 usecs.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2010-01-26 20:13:02 -07:00
Kevin Hilman
0d93d8bb7f OMAP: omap_device: track latency in nanoseconds
Rather than having to do a usecs = nsecs / NSECS_PER_USEC to
track latency in usecs, just track it in nanoseconds.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-12-11 17:00:44 -07:00
Kevin Hilman
d048ec7ab4 OMAP: omap_device: fix nsec/usec conversion in latency calculations
Use

   usecs = nsecs / NSEC_PER_USEC;

instead of

   usecs = nsecs * NSEC_PER_USEC;

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-12-11 17:00:44 -07:00
Kevin Hilman
d22926677f OMAP: omap_device: use read_persistent_clock() instead of getnstimeofday()
During suspend and resume, when omap_device deactivation and
activation is happening, the timekeeping subsystem has likely already
been suspended.  Thus getnstimeofday() will fail and trigger a WARN().

Use read_persistent_clock() instead of getnstimeofday() to avoid this.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-12-11 17:00:44 -07:00
Kevin Hilman
5f1b6ef76f OMAP: omap_device: use UINT_MAX for default wakeup latency limit
The _dev_wakeup_lat_limit field of struct omap_device is u32, so use
UINT_MAX instead of INT_MAX for the default maximum.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-12-11 17:00:44 -07:00
Tony Lindgren
ce491cf854 omap: headers: Move remaining headers from include/mach to include/plat
Move the remaining headers under plat-omap/include/mach
to plat-omap/include/plat. Also search and replace the
files using these headers to include using the right path.

This was done with:

#!/bin/bash
mach_dir_old="arch/arm/plat-omap/include/mach"
plat_dir_new="arch/arm/plat-omap/include/plat"
headers=$(cd $mach_dir_old && ls *.h)
omap_dirs="arch/arm/*omap*/ \
drivers/video/omap \
sound/soc/omap"
other_files="drivers/leds/leds-ams-delta.c \
drivers/mfd/menelaus.c \
drivers/mfd/twl4030-core.c \
drivers/mtd/nand/ams-delta.c"

for header in $headers; do
	old="#include <mach\/$header"
	new="#include <plat\/$header"
	for dir in $omap_dirs; do
		find $dir -type f -name \*.[chS] | \
			xargs sed -i "s/$old/$new/"
	done
	find drivers/ -type f -name \*omap*.[chS] | \
		xargs sed -i "s/$old/$new/"
	for file in $other_files; do
		sed -i "s/$old/$new/" $file
	done
done

for header in $(ls $mach_dir_old/*.h); do
	git mv $header $plat_dir_new/
done

Signed-off-by: Tony Lindgren <tony@atomide.com>
2009-10-20 09:40:47 -07:00
Tony Lindgren
f059429ea0 omap: Use getnstimeofday for omap_device
Use getnstimeofday for omap_device

Acked-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2009-10-19 15:25:24 -07:00
Paul Walmsley
b04b65ab5b OMAP2/3/4 core: create omap_device layer
The omap_device code provides a mapping of omap_hwmod structures into
the platform_device system, and includes some details on external
(board-level) integration.  This allows drivers to enable, idle, and
shutdown on-chip device resources, including clocks, regulators, etc.
The resources enabled and idled are dependent on the device's maximum
wakeup latency constraint (if present).

At the moment, omap_device functions are intended to be called from
platform_data function pointers.  Ideally in the future these
functions will be called from either subarchitecture-specific
platform_data activate, deactivate functions, or via an custom
bus/device type for OMAP.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Vikram Pandita <vikram.pandita@ti.com>
Cc: Sakari Poussa <sakari.poussa@nokia.com>
Cc: Anand Sawant <sawant@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Eric Thomas <ethomas@ti.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
2009-09-03 20:14:05 +03:00