The genpd_start_dev() routine used by pm_genpd_runtime_resume() to put "irq safe" devices into the full power state measures the time necessary to "start" the device and updates its PM QoS timing data if necessary. This may lead to a deadlock if the given device is a clock source and genpd_start_dev() is invoked from within the clock source's .enable() routine, which will happen if that routine uses pm_runtime_get_sync(), for example, to ensure that the device is operational.
For this reason, introduce a special routine analogous to genpd_start_dev(), called genpd_start_dev_no_timing(), that doesn't carry out the time measurement, and make pm_genpd_runtime_resume() use it instead of genpd_start_dev() to power up "irq safe" devices. Signed-off-by: Rafael J. Wysocki <[email protected]> --- drivers/base/power/domain.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) Index: linux/drivers/base/power/domain.c =================================================================== --- linux.orig/drivers/base/power/domain.c +++ linux/drivers/base/power/domain.c @@ -75,6 +75,12 @@ static int genpd_start_dev(struct generi start_latency_ns, "start"); } +static int genpd_start_dev_no_timing(struct generic_pm_domain *genpd, + struct device *dev) +{ + return GENPD_DEV_CALLBACK(genpd, int, start, dev); +} + static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd) { bool ret = false; @@ -626,7 +632,7 @@ static int pm_genpd_runtime_resume(struc /* If power.irq_safe, the PM domain is never powered off. */ if (dev->power.irq_safe) - return genpd_start_dev(genpd, dev); + return genpd_start_dev_no_timing(genpd, dev); mutex_lock(&genpd->lock); ret = __pm_genpd_poweron(genpd); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
