Hi Nishanth,
On Monday 28 December 2015 11:11 PM, Nishanth Menon wrote:
On 12/20/2015 11:46 PM, Keerthy wrote:
+linux-pm.
Thanks for looping!
In few rare conditions like during boot up the orderly_poweroff
function might not be able to complete fully leaving the device
running at dangerously high temperatures. Hence adding a backup
workqueue to act after a known period of time and poweroff the device.
Suggested-by: Nishanth Menon <nm@xxxxxx>
Reported-by: Nishanth Menon <nm@xxxxxx>
The specific case I hit was a critical temperature event as soon as
the hwmon device was probed (the driver tmp102 was a kernel module).
Signed-off-by: Keerthy <j-keerthy@xxxxxx>
---
drivers/thermal/Kconfig | 9 +++++++++
drivers/thermal/thermal_core.c | 26 ++++++++++++++++++++++++++
2 files changed, 35 insertions(+)
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 8cc4ac6..25584ee 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -92,6 +92,15 @@ config THERMAL_DEFAULT_GOV_POWER_ALLOCATOR
endchoice
+config THERMAL_BKUP_SHUTDOWN_DELAY_MS
+ int "Thermal shutdown backup delay in milli-seconds"
+ depends on THERMAL
+ default "5000"
+ ---help---
+ The number of milliseconds to delay after orderly_poweroff call.
Probably needs a rephrase.
Delay in milliseconds before the backup thermal shutdown is triggered.
+
+ Default: 5000 (5 seconds)
+
config THERMAL_GOV_FAIR_SHARE
bool "Fair-share thermal governor"
help
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index d9e525c..b793857 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -61,6 +61,12 @@ static DEFINE_MUTEX(thermal_governor_lock);
static struct thermal_governor *def_governor;
+#ifdef CONFIG_THERMAL_BKUP_SHUTDOWN_DELAY_MS
+#define BKUP_SHUTDOWN_DELAY CONFIG_THERMAL_BKUP_SHUTDOWN_DELAY_MS
+#else
+#define BKUP_SHUTDOWN_DELAY 5000
+#endif
+
I am not sure if this #ifdeffery is even needed.
Eduardo, Rui: If this is not the suggested technique, maybe you guys
could suggest how we could handle a case where userspace might be
hungup due to some reason and a case where a critical temperature
event in the middle of device probe was triggered?
Obviously, we'd like to take into consideration userspace latencies as
well- but that is very specific to fs being run.. not really a simple
problem, IMHO..
static struct thermal_governor *__find_governor(const char *name)
{
struct thermal_governor *pos;
@@ -423,6 +429,18 @@ static void handle_non_critical_trips(struct thermal_zone_device *tz,
def_governor->throttle(tz, trip);
}
+static void bkup_shutdown_func(struct work_struct *unused);
+static DECLARE_DELAYED_WORK(bkup_shutdown_work, bkup_shutdown_func);
+
+static void bkup_shutdown_func(struct work_struct *work)
+{
+ pr_warn("Orderly_poweroff has failed! Attempting kernel_power_off\n");
+ kernel_power_off();
+
+ pr_warn("kernel_power_off has failed! Attempting emergency_restart\n");
+ emergency_restart();
I think documentation is necessary that we are hoping for bootloader
to be able to detect and halt as needed -> risk here obviously is an
infinite reboot loop :( .
Agreed.
+}
+
static void handle_critical_trips(struct thermal_zone_device *tz,
int trip, enum thermal_trip_type trip_type)
{
@@ -443,6 +461,14 @@ static void handle_critical_trips(struct thermal_zone_device *tz,
dev_emerg(&tz->device,
"critical temperature reached(%d C),shutting down\n",
tz->temperature / 1000);
+ /**
needs to be kernel doc style?
+ * This is a backup option to shutdown the
+ * system in case orderly_poweroff
+ * fails
Maybe adjust to 80char?
Okay.
+ */
+ schedule_delayed_work(&bkup_shutdown_work,
+ msecs_to_jiffies(BKUP_SHUTDOWN_DELAY));
+
orderly_poweroff(true);
}
}
I will wait for Eduardo/Rui's inputs before posting the next version.
Best Regards,
Keerthy
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
