[PATCH v10 05/11] PM / devfreq: Don't take lock in devfreq_add_device
From: Leonard Crestez <hidden>
Date: 2019-10-31 21:36:34
Also in:
linux-pm
Subsystem:
device frequency (devfreq), the rest · Maintainers:
MyungJoo Ham, Kyungmin Park, Chanwoo Choi, Linus Torvalds
A device usually doesn't need to lock itself during initialization because it is not yet reachable from other threads. This simplifies the code and helps avoid recursive lock warnings. Signed-off-by: Leonard Crestez <redacted> Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> --- drivers/devfreq/devfreq.c | 13 +------------ 1 file changed, 1 insertion(+), 12 deletions(-)
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index d89de2c37dfa..ab12fd22aa08 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c@@ -635,11 +635,10 @@ struct devfreq *devfreq_add_device(struct device *dev, err = -ENOMEM; goto err_out; } mutex_init(&devfreq->lock); - mutex_lock(&devfreq->lock); devfreq->dev.parent = dev; devfreq->dev.class = devfreq_class; devfreq->dev.release = devfreq_dev_release; device_initialize(&devfreq->dev); INIT_LIST_HEAD(&devfreq->node);
@@ -649,28 +648,24 @@ struct devfreq *devfreq_add_device(struct device *dev, devfreq->last_status.current_frequency = profile->initial_freq; devfreq->data = data; devfreq->nb.notifier_call = devfreq_notifier_call; if (!devfreq->profile->max_state && !devfreq->profile->freq_table) { - mutex_unlock(&devfreq->lock); err = set_freq_table(devfreq); if (err < 0) goto err_dev; - mutex_lock(&devfreq->lock); } devfreq->scaling_min_freq = find_available_min_freq(devfreq); if (!devfreq->scaling_min_freq) { - mutex_unlock(&devfreq->lock); err = -EINVAL; goto err_dev; } devfreq->min_freq = devfreq->scaling_min_freq; devfreq->scaling_max_freq = find_available_max_freq(devfreq); if (!devfreq->scaling_max_freq) { - mutex_unlock(&devfreq->lock); err = -EINVAL; goto err_dev; } devfreq->max_freq = devfreq->scaling_max_freq;
@@ -681,21 +676,19 @@ struct devfreq *devfreq_add_device(struct device *dev, array3_size(sizeof(unsigned int), devfreq->profile->max_state, devfreq->profile->max_state), GFP_KERNEL); if (!devfreq->trans_table) { - mutex_unlock(&devfreq->lock); err = -ENOMEM; goto err_dev; } devfreq->time_in_state = devm_kcalloc(&devfreq->dev, devfreq->profile->max_state, sizeof(unsigned long), GFP_KERNEL); if (!devfreq->time_in_state) { - mutex_unlock(&devfreq->lock); err = -ENOMEM; goto err_dev; } devfreq->last_stat_updated = jiffies;
@@ -703,16 +696,12 @@ struct devfreq *devfreq_add_device(struct device *dev, srcu_init_notifier_head(&devfreq->transition_notifier_list); dev_set_name(&devfreq->dev, "devfreq%d", atomic_inc_return(&devfreq_no)); err = device_add(&devfreq->dev); - if (err) { - mutex_unlock(&devfreq->lock); + if (err) goto err_dev; - } - - mutex_unlock(&devfreq->lock); mutex_lock(&devfreq_list_lock); governor = try_then_request_governor(devfreq->governor_name); if (IS_ERR(governor)) {
--
2.17.1
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