From 1d4a9c17d4d204a159139361e8d4db7f9f267879 Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Sun, 22 Feb 2015 21:16:49 -0800 Subject: PM / sleep: add configurable delay for pm_test When CONFIG_PM_DEBUG=y, we provide a sysfs file (/sys/power/pm_test) for selecting one of a few suspend test modes, where rather than entering a full suspend state, the kernel will perform some subset of suspend steps, wait 5 seconds, and then resume back to normal operation. This mode is useful for (among other things) observing the state of the system just before entering a sleep mode, for debugging or analysis purposes. However, a constant 5 second wait is not sufficient for some sorts of analysis; for example, on an SoC, one might want to use external tools to probe the power states of various on-chip controllers or clocks. This patch turns this 5 second delay into a configurable module parameter, so users can determine how long to wait in this pseudo-suspend state before resuming the system. Example (wait 30 seconds); # echo 30 > /sys/module/suspend/parameters/pm_test_delay # echo core > /sys/power/pm_test # time echo mem > /sys/power/state ... [ 17.583625] suspend debug: Waiting for 30 second(s). ... real 0m30.381s user 0m0.017s sys 0m0.080s Signed-off-by: Brian Norris Acked-by: Pavel Machek Reviewed-by: Kevin Cernekee Acked-by: Florian Fainelli Signed-off-by: Rafael J. Wysocki --- Documentation/kernel-parameters.txt | 7 +++++++ Documentation/power/basic-pm-debugging.txt | 10 ++++++---- 2 files changed, 13 insertions(+), 4 deletions(-) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index bfcb1a62a7b4..8b1fa5e129ac 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3462,6 +3462,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. improve throughput, but will also increase the amount of memory reserved for use by the client. + suspend.pm_test_delay= + [SUSPEND] + Sets the number of seconds to remain in a suspend test + mode before resuming the system (see + /sys/power/pm_test). Only available when CONFIG_PM_DEBUG + is set. Default value is 5. + swapaccount=[0|1] [KNL] Enable accounting of swap in memory resource controller if no parameter or 1 is given or disable diff --git a/Documentation/power/basic-pm-debugging.txt b/Documentation/power/basic-pm-debugging.txt index edeecd447d23..b96098ccfe69 100644 --- a/Documentation/power/basic-pm-debugging.txt +++ b/Documentation/power/basic-pm-debugging.txt @@ -75,12 +75,14 @@ you should do the following: # echo platform > /sys/power/disk # echo disk > /sys/power/state -Then, the kernel will try to freeze processes, suspend devices, wait 5 seconds, -resume devices and thaw processes. If "platform" is written to +Then, the kernel will try to freeze processes, suspend devices, wait a few +seconds (5 by default, but configurable by the suspend.pm_test_delay module +parameter), resume devices and thaw processes. If "platform" is written to /sys/power/pm_test , then after suspending devices the kernel will additionally invoke the global control methods (eg. ACPI global control methods) used to -prepare the platform firmware for hibernation. Next, it will wait 5 seconds and -invoke the platform (eg. ACPI) global methods used to cancel hibernation etc. +prepare the platform firmware for hibernation. Next, it will wait a +configurable number of seconds and invoke the platform (eg. ACPI) global +methods used to cancel hibernation etc. Writing "none" to /sys/power/pm_test causes the kernel to switch to the normal hibernation/suspend operations. Also, when open for reading, /sys/power/pm_test -- cgit v1.2.3 From 56b858dfad9b97aea88f9fe87b1468ddaf154c94 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Tue, 17 Mar 2015 12:40:12 +0200 Subject: ACPI: Update GPIO documentation to mention _DSD Make sure that the ACPI enumeration.txt provides latest information on how to describe and retrieve GPIOs now that we can take advantage of _DSD device properties. Signed-off-by: Mika Westerberg Signed-off-by: Rafael J. Wysocki --- Documentation/acpi/enumeration.txt | 26 +++++++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-) (limited to 'Documentation') diff --git a/Documentation/acpi/enumeration.txt b/Documentation/acpi/enumeration.txt index 9b121a569ab4..750401f91341 100644 --- a/Documentation/acpi/enumeration.txt +++ b/Documentation/acpi/enumeration.txt @@ -254,8 +254,13 @@ GPIO support ~~~~~~~~~~~~ ACPI 5 introduced two new resources to describe GPIO connections: GpioIo and GpioInt. These resources are used be used to pass GPIO numbers used by -the device to the driver. For example: +the device to the driver. ACPI 5.1 extended this with _DSD (Device +Specific Data) which made it possible to name the GPIOs among other things. +For example: + +Device (DEV) +{ Method (_CRS, 0, NotSerialized) { Name (SBUF, ResourceTemplate() @@ -285,6 +290,18 @@ the device to the driver. For example: Return (SBUF) } + // ACPI 5.1 _DSD used for naming the GPIOs + Name (_DSD, Package () + { + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), + Package () + { + Package () {"power-gpios", Package() {^DEV, 0, 0, 0 }}, + Package () {"irq-gpios", Package() {^DEV, 1, 0, 0 }}, + } + }) + ... + These GPIO numbers are controller relative and path "\\_SB.PCI0.GPI0" specifies the path to the controller. In order to use these GPIOs in Linux we need to translate them to the corresponding Linux GPIO descriptors. @@ -300,11 +317,11 @@ a code like this: struct gpio_desc *irq_desc, *power_desc; - irq_desc = gpiod_get_index(dev, NULL, 1); + irq_desc = gpiod_get(dev, "irq"); if (IS_ERR(irq_desc)) /* handle error */ - power_desc = gpiod_get_index(dev, NULL, 0); + power_desc = gpiod_get(dev, "power"); if (IS_ERR(power_desc)) /* handle error */ @@ -313,6 +330,9 @@ a code like this: There are also devm_* versions of these functions which release the descriptors once the device is released. +See Documentation/acpi/gpio-properties.txt for more information about the +_DSD binding related to GPIOs. + MFD devices ~~~~~~~~~~~ The MFD devices register their children as platform devices. For the child -- cgit v1.2.3