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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2024-01-22 12:22:38 +0100 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2024-01-26 19:38:36 +0100 |
commit | 86686b8f7ad3abe5aca17643efcee2bbce31a8f7 (patch) | |
tree | 7feda8e38675c730ae240e35eb747849ed159332 /drivers/base/power | |
parent | b017500ab53c06441ff7d3a681484e37039b4f57 (diff) | |
download | linux-stable-86686b8f7ad3abe5aca17643efcee2bbce31a8f7.tar.gz linux-stable-86686b8f7ad3abe5aca17643efcee2bbce31a8f7.tar.bz2 linux-stable-86686b8f7ad3abe5aca17643efcee2bbce31a8f7.zip |
PM: sleep: Simplify dpm_suspended_list walk in dpm_resume()
Notice that devices can be moved to dpm_prepared_list before running
their resume callbacks, in analogy with dpm_noirq_resume_devices() and
dpm_resume_early(), because doing so will not affect the final ordering
of that list.
Namely, if a device is the first dpm_suspended_list entry while
dpm_list_mtx is held, it has not been removed so far and it cannot be
removed until dpm_list_mtx is released, so moving it to dpm_prepared_list
at that point is valid. If it is removed later, while its resume
callback is running, it will be deleted from dpm_prepared_list without
changing the ordering of the other devices in that list.
Accordingly, rearrange the while () loop in dpm_resume() to move
devices to dpm_prepared_list before running their resume callbacks and
implify the locking and device reference counting in it.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Diffstat (limited to 'drivers/base/power')
-rw-r--r-- | drivers/base/power/main.c | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index fadcd0379dc2..10984aa5192b 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -1017,25 +1017,19 @@ void dpm_resume(pm_message_t state) while (!list_empty(&dpm_suspended_list)) { dev = to_device(dpm_suspended_list.next); - - get_device(dev); + list_move_tail(&dev->power.entry, &dpm_prepared_list); if (!dev->power.async_in_progress) { + get_device(dev); + mutex_unlock(&dpm_list_mtx); device_resume(dev, state, false); + put_device(dev); + mutex_lock(&dpm_list_mtx); } - - if (!list_empty(&dev->power.entry)) - list_move_tail(&dev->power.entry, &dpm_prepared_list); - - mutex_unlock(&dpm_list_mtx); - - put_device(dev); - - mutex_lock(&dpm_list_mtx); } mutex_unlock(&dpm_list_mtx); async_synchronize_full(); |