From 632e270e01d8a1ee9e8ea56c83028727f17b1d17 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 1 Jul 2011 22:29:15 +0200 Subject: [PATCH] PM / Runtime: Return special error code if runtime PM is disabled Some callers of pm_runtime_get_sync() and other runtime PM helper functions, scsi_autopm_get_host() and scsi_autopm_get_device() in particular, need to distinguish error codes returned when runtime PM is disabled (i.e. power.disable_depth is nonzero for the given device) from error codes returned in other situations. For this reason, make the runtime PM helper functions return -EACCES when power.disable_depth is nonzero and ensure that this error code won't be returned by them in any other circumstances. Modify scsi_autopm_get_host() and scsi_autopm_get_device() to check the error code returned by pm_runtime_get_sync() and ignore -EACCES. Signed-off-by: Rafael J. Wysocki --- Documentation/power/runtime_pm.txt | 6 ++++-- drivers/base/power/runtime.c | 9 +++++---- drivers/scsi/scsi_pm.c | 8 ++++---- 3 files changed, 13 insertions(+), 10 deletions(-) diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt index 513c52ef5a42..0ec3d610fc9a 100644 --- a/Documentation/power/runtime_pm.txt +++ b/Documentation/power/runtime_pm.txt @@ -291,7 +291,8 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: - execute the subsystem-level suspend callback for the device; returns 0 on success, 1 if the device's run-time PM status was already 'suspended', or error code on failure, where -EAGAIN or -EBUSY means it is safe to attempt - to suspend the device again in future + to suspend the device again in future and -EACCES means that + 'power.disable_depth' is different from 0 int pm_runtime_autosuspend(struct device *dev); - same as pm_runtime_suspend() except that the autosuspend delay is taken @@ -304,7 +305,8 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: success, 1 if the device's run-time PM status was already 'active' or error code on failure, where -EAGAIN means it may be safe to attempt to resume the device again in future, but 'power.runtime_error' should be - checked additionally + checked additionally, and -EACCES means that 'power.disable_depth' is + different from 0 int pm_request_idle(struct device *dev); - submit a request to execute the subsystem-level idle callback for the diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 5f5c4236f006..ee99025be6b3 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -135,8 +135,9 @@ static int rpm_check_suspend_allowed(struct device *dev) if (dev->power.runtime_error) retval = -EINVAL; - else if (atomic_read(&dev->power.usage_count) > 0 - || dev->power.disable_depth > 0) + else if (dev->power.disable_depth > 0) + retval = -EACCES; + else if (atomic_read(&dev->power.usage_count) > 0) retval = -EAGAIN; else if (!pm_children_suspended(dev)) retval = -EBUSY; @@ -262,7 +263,7 @@ static int rpm_callback(int (*cb)(struct device *), struct device *dev) spin_lock_irq(&dev->power.lock); } dev->power.runtime_error = retval; - return retval; + return retval != -EACCES ? retval : -EIO; } /** @@ -458,7 +459,7 @@ static int rpm_resume(struct device *dev, int rpmflags) if (dev->power.runtime_error) retval = -EINVAL; else if (dev->power.disable_depth > 0) - retval = -EAGAIN; + retval = -EACCES; if (retval) goto out; diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c index d70e91ae60af..d82a023a9015 100644 --- a/drivers/scsi/scsi_pm.c +++ b/drivers/scsi/scsi_pm.c @@ -144,9 +144,9 @@ int scsi_autopm_get_device(struct scsi_device *sdev) int err; err = pm_runtime_get_sync(&sdev->sdev_gendev); - if (err < 0) + if (err < 0 && err !=-EACCES) pm_runtime_put_sync(&sdev->sdev_gendev); - else if (err > 0) + else err = 0; return err; } @@ -173,9 +173,9 @@ int scsi_autopm_get_host(struct Scsi_Host *shost) int err; err = pm_runtime_get_sync(&shost->shost_gendev); - if (err < 0) + if (err < 0 && err !=-EACCES) pm_runtime_put_sync(&shost->shost_gendev); - else if (err > 0) + else err = 0; return err; } -- 2.34.1