On Mon, Mar 5, 2018 at 10:29 AM, Feng Kan <fkan@xxxxxxx> wrote:
> 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: Feng Kan <fkan@xxxxxxx>
> Signed-off-by: Toan Le <toanle@xxxxxxx>
> ---
> V3:
> 1. additional code comment changes
> V2:
> 1. change patch title from "move device and its children..."
> 2. move define based on Bjorn's comment
> 3. rename function name and comment content
>
> 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 d800de6..a75c302 100644
> --- a/drivers/base/base.h
> +++ b/drivers/base/base.h
> @@ -161,3 +161,6 @@ static inline void module_remove_driver(struct device_driver *drv) { }
> 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 110230d..3b37906 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -148,6 +148,26 @@ static int device_reorder_to_tail(struct device *dev, void *not_used)
> }
>
> /**
> + * device_pm_move_to_tail - Move set of devices to the end of device lists
> + * @dev: current device pointer
> + *
> + * This is a device_reorder_to_tail() wrapper taking the requisite locks.
> + *
> + * It moves the device 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.
> * @supplier: Supplier end of the link.
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index 2c964f5..96fab29 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -123,9 +123,7 @@ 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)
> --
> 1.8.3.1
>
Hi, just wanted to check if there is anything else I need to change on
this. Thanks.
