Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | [PATCH 2/6] PM / Domains: Fix hibernation restore of devices | Date | Tue, 13 Mar 2012 01:24:59 +0100 |
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From: Rafael J. Wysocki <rjw@sisk.pl>
During resume from hibernation pm_genpd_restore_noirq() has to deal with software state left by pm_genpd_suspend_noirq() and unknown hardware state (the boot kernel may leave all PM domains and devices in arbitrary states). For this reason, make it attempt to power cycle each domain when before resuming its first device to possibly get rid of any unwanted hardware state that may interfere with genpd_start_dev() later on.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- drivers/base/power/domain.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-)
Index: linux/drivers/base/power/domain.c =================================================================== --- linux.orig/drivers/base/power/domain.c +++ linux/drivers/base/power/domain.c @@ -770,8 +770,10 @@ static int pm_genpd_prepare(struct devic genpd_acquire_lock(genpd); - if (genpd->prepared_count++ == 0) + if (genpd->prepared_count++ == 0) { + genpd->suspended_count = 0; genpd->suspend_power_off = genpd->status == GPD_STATE_POWER_OFF; + } genpd_release_lock(genpd); @@ -1103,20 +1105,24 @@ static int pm_genpd_restore_noirq(struct * Since all of the "noirq" callbacks are executed sequentially, it is * guaranteed that this function will never run twice in parallel for * the same PM domain, so it is not necessary to use locking here. + * + * At this point suspended_count == 0 means this routing is being run + * for the first time for the given domain in the present cycle. */ - genpd->status = GPD_STATE_POWER_OFF; - if (genpd->suspend_power_off) { + if (genpd->suspended_count++ == 0) { /* - * The boot kernel might put the domain into the power on state, - * so make sure it really is powered off. + * The boot kernel might put the domain into arbitrary state, + * so make sure it is powered off. */ + genpd->status = GPD_STATE_POWER_OFF; if (genpd->power_off) genpd->power_off(genpd); - return 0; } + if (genpd->suspend_power_off) + return 0; + pm_genpd_poweron(genpd); - genpd->suspended_count--; return genpd_start_dev(genpd, dev); } @@ -1623,7 +1629,6 @@ void pm_genpd_init(struct generic_pm_dom genpd->poweroff_task = NULL; genpd->resume_count = 0; genpd->device_count = 0; - genpd->suspended_count = 0; genpd->max_off_time_ns = -1; genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend; genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume;
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