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author | Rafael J. Wysocki <rjw@sisk.pl> | 2012-06-16 00:02:34 +0200 |
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committer | Rafael J. Wysocki <rjw@sisk.pl> | 2012-07-01 13:31:29 +0200 |
commit | 80de3d7f416f1accd03f2e519ead32d6fde4fcf4 (patch) | |
tree | 4f6c5b3a6355fc6d9f6423b11afa28b119eb6dbc /drivers/base | |
parent | 0b589741b8b83a33e25fb32bb714ea1b972af5aa (diff) | |
download | linux-3.10-80de3d7f416f1accd03f2e519ead32d6fde4fcf4.tar.gz linux-3.10-80de3d7f416f1accd03f2e519ead32d6fde4fcf4.tar.bz2 linux-3.10-80de3d7f416f1accd03f2e519ead32d6fde4fcf4.zip |
PM / Domains: Do not stop devices after restoring their states
While resuming a device belonging to a PM domain,
pm_genpd_runtime_resume() calls __pm_genpd_restore_device() to
restore its state, if necessary. The latter starts the device,
using genpd_start_dev(), restores its state, using
genpd_restore_dev(), and then stops it, using genpd_stop_dev().
However, this last operation is not necessary, because the
device is supposed to be operational after pm_genpd_runtime_resume()
has returned and because of it pm_genpd_runtime_resume() has to
call genpd_start_dev() once again for the "restored" device, which
is inefficient.
To make things more efficient, remove the call to genpd_stop_dev()
from __pm_genpd_restore_device() and the direct call to
genpd_start_dev() from pm_genpd_runtime_resume(). [Of course,
genpd_start_dev() still has to be called by it for devices with the
power.irq_safe flag set, because __pm_genpd_restore_device() is not
executed for them.]
This change has been tested on the SH7372 Mackerel board.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'drivers/base')
-rw-r--r-- | drivers/base/power/domain.c | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 49fdd4002b9..da1d52576ec 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -339,19 +339,16 @@ static void __pm_genpd_restore_device(struct pm_domain_data *pdd, { struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd); struct device *dev = pdd->dev; + bool need_restore = gpd_data->need_restore; - if (!gpd_data->need_restore) - return; - + gpd_data->need_restore = false; mutex_unlock(&genpd->lock); genpd_start_dev(genpd, dev); - genpd_restore_dev(genpd, dev); - genpd_stop_dev(genpd, dev); + if (need_restore) + genpd_restore_dev(genpd, dev); mutex_lock(&genpd->lock); - - gpd_data->need_restore = false; } /** @@ -595,7 +592,7 @@ static int pm_genpd_runtime_resume(struct device *dev) /* If power.irq_safe, the PM domain is never powered off. */ if (dev->power.irq_safe) - goto out; + return genpd_start_dev(genpd, dev); mutex_lock(&genpd->lock); ret = __pm_genpd_poweron(genpd); @@ -628,9 +625,6 @@ static int pm_genpd_runtime_resume(struct device *dev) wake_up_all(&genpd->status_wait_queue); mutex_unlock(&genpd->lock); - out: - genpd_start_dev(genpd, dev); - return 0; } |