From 494fd7b7ad10c33d3a7ff7d10b71b3ecad10474a Mon Sep 17 00:00:00 2001 From: Feng Kan Date: Tue, 10 Apr 2018 16:57:06 -0700 Subject: [PATCH] PM / core: fix deferred probe breaking suspend resume order When bridge and its endpoint is enumerated the devices are added to the dpm list. Afterward, the bridge defers probe when IOMMU is not ready. This causes the bridge to be moved to the end of the dpm list when deferred probe kicks in. The order of the dpm list for bridge and endpoint is reversed. Add reordering code to move the bridge and its children and consumers to the end of the pm list so the order for suspend and resume is not altered. The code also move device and its children and consumers to the tail of device_kset list if it is registered. Signed-off-by: Toan Le Signed-off-by: Feng Kan Reviewed-by: Greg Kroah-Hartman Signed-off-by: Rafael J. Wysocki --- drivers/base/base.h | 3 +++ drivers/base/core.c | 20 ++++++++++++++++++++ drivers/base/dd.c | 4 +--- 3 files changed, 24 insertions(+), 3 deletions(-) diff --git a/drivers/base/base.h b/drivers/base/base.h index d800de650fa5..a75c3025fb78 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -161,3 +161,6 @@ extern void device_links_driver_cleanup(struct device *dev); extern void device_links_no_driver(struct device *dev); extern bool device_links_busy(struct device *dev); extern void device_links_unbind_consumers(struct device *dev); + +/* device pm support */ +void device_pm_move_to_tail(struct device *dev); diff --git a/drivers/base/core.c b/drivers/base/core.c index b610816eb887..ad7b50897bcc 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -144,6 +144,26 @@ static int device_reorder_to_tail(struct device *dev, void *not_used) return 0; } +/** + * device_pm_move_to_tail - Move set of devices to the end of device lists + * @dev: Device to move + * + * This is a device_reorder_to_tail() wrapper taking the requisite locks. + * + * It moves the @dev along with all of its children and all of its consumers + * to the ends of the device_kset and dpm_list, recursively. + */ +void device_pm_move_to_tail(struct device *dev) +{ + int idx; + + idx = device_links_read_lock(); + device_pm_lock(); + device_reorder_to_tail(dev, NULL); + device_pm_unlock(); + device_links_read_unlock(idx); +} + /** * device_link_add - Create a link between two devices. * @consumer: Consumer end of the link. diff --git a/drivers/base/dd.c b/drivers/base/dd.c index c9f54089429b..10454fe54482 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -122,9 +122,7 @@ static void deferred_probe_work_func(struct work_struct *work) * the list is a good order for suspend but deferred * probe makes that very unsafe. */ - device_pm_lock(); - device_pm_move_last(dev); - device_pm_unlock(); + device_pm_move_to_tail(dev); dev_dbg(dev, "Retrying from deferred list\n"); if (initcall_debug && !initcalls_done)