From e8bf17d58a4db4b4f38617925414097f12e0d509 Mon Sep 17 00:00:00 2001 From: Evan Green Date: Mon, 22 Aug 2022 14:40:40 -0700 Subject: [PATCH] platform/chrome: cros_ec: Expose suspend_timeout_ms in debugfs In modern Chromebooks, the embedded controller has a mechanism where it will watch a hardware-controlled line that toggles in suspend, and wake the system up if an expected sleep transition didn't occur. This can be very useful for detecting power management issues where the system appears to suspend, but doesn't actually reach its lowest expected power states. Sometimes it's useful in debug and test scenarios to be able to control the duration of that timeout, or even disable the EC timeout mechanism altogether. Add a debugfs control to set the timeout to values other than the EC-defined default, for more convenient debug and development iteration. Signed-off-by: Evan Green Reviewed-by: Prashant Malani Reviewed-by: Stephen Boyd Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20220822144026.v3.1.Idd188ff3f9caddebc17ac357a13005f93333c21f@changeid [tzungbi: fix one nit in Documentation/ABI/testing/debugfs-cros-ec.] Signed-off-by: Tzung-Bi Shih --- Documentation/ABI/testing/debugfs-cros-ec | 22 ++++++++++++++++++++++ drivers/platform/chrome/cros_ec.c | 3 ++- drivers/platform/chrome/cros_ec_debugfs.c | 3 +++ include/linux/platform_data/cros_ec_proto.h | 1 + 4 files changed, 28 insertions(+), 1 deletion(-) diff --git a/Documentation/ABI/testing/debugfs-cros-ec b/Documentation/ABI/testing/debugfs-cros-ec index 1fe0add..9a040c6 100644 --- a/Documentation/ABI/testing/debugfs-cros-ec +++ b/Documentation/ABI/testing/debugfs-cros-ec @@ -54,3 +54,25 @@ Description: this feature. Output will be in the format: "0x%08x\n". + +What: /sys/kernel/debug//suspend_timeout_ms +Date: August 2022 +KernelVersion: 6.1 +Description: + Some ECs have a feature where they will track transitions of + a hardware-controlled sleep line, such as Intel's SLP_S0 line, + in order to detect cases where a system failed to go into deep + sleep states. The suspend_timeout_ms file controls the amount of + time in milliseconds the EC will wait before declaring a sleep + timeout event and attempting to wake the system. + + Supply 0 to use the default value coded into EC firmware. Supply + 65535 (EC_HOST_SLEEP_TIMEOUT_INFINITE) to disable the EC sleep + failure detection mechanism. Values in between 0 and 65535 + indicate the number of milliseconds the EC should wait after a + sleep transition before declaring a timeout. This includes both + the duration after a sleep command was received but before the + hardware line changed, as well as the duration between when the + hardware line changed and the kernel sent an EC resume command. + + Output will be in the format: "%u\n". diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c index 8aace50..32140a7 100644 --- a/drivers/platform/chrome/cros_ec.c +++ b/drivers/platform/chrome/cros_ec.c @@ -115,7 +115,7 @@ static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event) if (ec_dev->host_sleep_v1) { buf.u.req1.sleep_event = sleep_event; buf.u.req1.suspend_params.sleep_timeout_ms = - EC_HOST_SLEEP_TIMEOUT_DEFAULT; + ec_dev->suspend_timeout_ms; buf.msg.outsize = sizeof(buf.u.req1); if ((sleep_event == HOST_SLEEP_EVENT_S3_RESUME) || @@ -188,6 +188,7 @@ int cros_ec_register(struct cros_ec_device *ec_dev) ec_dev->max_passthru = 0; ec_dev->ec = NULL; ec_dev->pd = NULL; + ec_dev->suspend_timeout_ms = EC_HOST_SLEEP_TIMEOUT_DEFAULT; ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL); if (!ec_dev->din) diff --git a/drivers/platform/chrome/cros_ec_debugfs.c b/drivers/platform/chrome/cros_ec_debugfs.c index 0dbceee..4e63adf 100644 --- a/drivers/platform/chrome/cros_ec_debugfs.c +++ b/drivers/platform/chrome/cros_ec_debugfs.c @@ -470,6 +470,9 @@ static int cros_ec_debugfs_probe(struct platform_device *pd) debugfs_create_x32("last_resume_result", 0444, debug_info->dir, &ec->ec_dev->last_resume_result); + debugfs_create_u16("suspend_timeout_ms", 0664, debug_info->dir, + &ec->ec_dev->suspend_timeout_ms); + ec->debug_info = debug_info; dev_set_drvdata(&pd->dev, ec); diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h index 408b29c..e43107e 100644 --- a/include/linux/platform_data/cros_ec_proto.h +++ b/include/linux/platform_data/cros_ec_proto.h @@ -169,6 +169,7 @@ struct cros_ec_device { int event_size; u32 host_event_wake_mask; u32 last_resume_result; + u16 suspend_timeout_ms; ktime_t last_event_time; struct notifier_block notifier_ready; -- 2.7.4