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Commit 64b4055c authored by Naresh Malladi's avatar Naresh Malladi Committed by Maulik Shah
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drivers: 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 c619a7c2

drivers/cpuidle/lpm-levels.c

+3 −4
Original line number Original line Diff line number Diff line
@@ -571,22 +571,21 @@ static int cpu_power_select(struct cpuidle_device *dev, 
	int best_level = -1;

	int best_level = -1;

	uint32_t latency_us = pm_qos_request_for_cpu(PM_QOS_CPU_DMA_LATENCY,

	uint32_t latency_us = pm_qos_request_for_cpu(PM_QOS_CPU_DMA_LATENCY,

							dev->cpu);

							dev->cpu);

	uint32_t sleep_us =

	s64 sleep_us = ktime_to_us(tick_nohz_get_sleep_length());

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

	uint32_t modified_time_us = 0;

	uint32_t modified_time_us = 0;

	uint32_t next_event_us = 0;

	uint32_t next_event_us = 0;

	int i, idx_restrict;

	int i, idx_restrict;

	uint32_t lvl_latency_us = 0;

	uint32_t lvl_latency_us = 0;

	uint64_t predicted = 0;

	uint64_t predicted = 0;

	uint32_t htime = 0, idx_restrict_time = 0;

	uint32_t htime = 0, idx_restrict_time = 0;

	uint32_t next_wakeup_us = sleep_us;

	uint32_t next_wakeup_us = (uint32_t)sleep_us;

	uint32_t *min_residency = get_per_cpu_min_residency(dev->cpu);

	uint32_t *min_residency = get_per_cpu_min_residency(dev->cpu);

	uint32_t *max_residency = get_per_cpu_max_residency(dev->cpu);

	uint32_t *max_residency = get_per_cpu_max_residency(dev->cpu);





	if (!cpu)

	if (!cpu)

		return -EINVAL;

		return -EINVAL;





	if (sleep_disabled)

	if (sleep_disabled || sleep_us < 0)

		return 0;

		return 0;





	idx_restrict = cpu->nlevels + 1;

	idx_restrict = cpu->nlevels + 1;