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Commit a791bcff authored by Naresh Malladi's avatar Naresh Malladi
Browse files

cpuidle: lpm-levels: Check for negative sleep times 



A negative sleep time could be interpreted as a large positive sleep
time when its casted to a unsigned type. This could result in CPU sleeping
for a longer than expected duration resulting in missed interrupts.

Change-Id: I472f355c8ba392ab46d53fceddb448f7e35c178e
Signed-off-by: default avatarMahesh Sivasubramanian <msivasub@codeaurora.org>
Signed-off-by: default avatarMaulik Shah <mkshah@codeaurora.org>
Signed-off-by: default avatarNaresh Malladi <namall@codeaurora.org>
parent 38afda62

drivers/cpuidle/lpm-levels.c

+3 −4
Original line number Diff line number Diff line
@@ -445,8 +445,7 @@ static int cpu_power_select(struct cpuidle_device *dev, 
	int best_level = -1;

	uint32_t latency_us = pm_qos_request_for_cpu(PM_QOS_CPU_DMA_LATENCY,

							dev->cpu);

	uint32_t sleep_us =

		(uint32_t)(ktime_to_us(tick_nohz_get_sleep_length()));

	s64 sleep_us = ktime_to_us(tick_nohz_get_sleep_length());

	uint32_t modified_time_us = 0;

	uint32_t next_event_us = 0;

	int i;
@@ -456,7 +455,7 @@ static int cpu_power_select(struct cpuidle_device *dev, 
	if (!cpu)

		return -EINVAL;



	if (sleep_disabled)

	if (sleep_disabled || sleep_us  < 0)

		return 0;



	next_event_us = (uint32_t)(ktime_to_us(get_next_event_time(dev->cpu)));
@@ -464,7 +463,7 @@ static int cpu_power_select(struct cpuidle_device *dev, 
	for (i = 0; i < cpu->nlevels; i++) {

		struct lpm_cpu_level *level = &cpu->levels[i];

		struct power_params *pwr_params = &level->pwr;

		uint32_t next_wakeup_us = sleep_us;

		uint32_t next_wakeup_us = (uint32_t)sleep_us;

		enum msm_pm_sleep_mode mode = level->mode;

		bool allow;