diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 25371c91a58fe7cc45a0ae681221d25f801cafb7..8cca52be993f4c831660f0c0d13bac290a37e4de 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -37,6 +37,10 @@ static HLIST_HEAD(clk_root_list);
static HLIST_HEAD(clk_orphan_list);
static LIST_HEAD(clk_notifier_list);
+/* List of registered clks that use runtime PM */
+static HLIST_HEAD(clk_rpm_list);
+static DEFINE_MUTEX(clk_rpm_list_lock);
+
static const struct hlist_head *all_lists[] = {
&clk_root_list,
&clk_orphan_list,
@@ -59,6 +63,7 @@ struct clk_core {
struct clk_hw *hw;
struct module *owner;
struct device *dev;
+ struct hlist_node rpm_node;
struct device_node *of_node;
struct clk_core *parent;
struct clk_parent_map *parents;
@@ -122,6 +127,89 @@ static void clk_pm_runtime_put(struct clk_core *core)
pm_runtime_put_sync(core->dev);
}
+/**
+ * clk_pm_runtime_get_all() - Runtime "get" all clk provider devices
+ *
+ * Call clk_pm_runtime_get() on all runtime PM enabled clks in the clk tree so
+ * that disabling unused clks avoids a deadlock where a device is runtime PM
+ * resuming/suspending and the runtime PM callback is trying to grab the
+ * prepare_lock for something like clk_prepare_enable() while
+ * clk_disable_unused_subtree() holds the prepare_lock and is trying to runtime
+ * PM resume/suspend the device as well.
+ *
+ * Context: Acquires the 'clk_rpm_list_lock' and returns with the lock held on
+ * success. Otherwise the lock is released on failure.
+ *
+ * Return: 0 on success, negative errno otherwise.
+ */
+static int clk_pm_runtime_get_all(void)
+{
+ int ret;
+ struct clk_core *core, *failed;
+
+ /*
+ * Grab the list lock to prevent any new clks from being registered
+ * or unregistered until clk_pm_runtime_put_all().
+ */
+ mutex_lock(&clk_rpm_list_lock);
+
+ /*
+ * Runtime PM "get" all the devices that are needed for the clks
+ * currently registered. Do this without holding the prepare_lock, to
+ * avoid the deadlock.
+ */
+ hlist_for_each_entry(core, &clk_rpm_list, rpm_node) {
+ ret = clk_pm_runtime_get(core);
+ if (ret) {
+ failed = core;
+ pr_err("clk: Failed to runtime PM get '%s' for clk '%s'\n",
+ dev_name(failed->dev), failed->name);
+ goto err;
+ }
+ }
+
+ return 0;
+
+err:
+ hlist_for_each_entry(core, &clk_rpm_list, rpm_node) {
+ if (core == failed)
+ break;
+
+ clk_pm_runtime_put(core);
+ }
+ mutex_unlock(&clk_rpm_list_lock);
+
+ return ret;
+}
+
+/**
+ * clk_pm_runtime_put_all() - Runtime "put" all clk provider devices
+ *
+ * Put the runtime PM references taken in clk_pm_runtime_get_all() and release
+ * the 'clk_rpm_list_lock'.
+ */
+static void clk_pm_runtime_put_all(void)
+{
+ struct clk_core *core;
+
+ hlist_for_each_entry(core, &clk_rpm_list, rpm_node)
+ clk_pm_runtime_put(core);
+ mutex_unlock(&clk_rpm_list_lock);
+}
+
+static void clk_pm_runtime_init(struct clk_core *core)
+{
+ struct device *dev = core->dev;
+
+ if (dev && pm_runtime_enabled(dev)) {
+ core->rpm_enabled = true;
+
+ mutex_lock(&clk_rpm_list_lock);
+ hlist_add_head(&core->rpm_node, &clk_rpm_list);
+ mutex_unlock(&clk_rpm_list_lock);
+ }
+}
+
/*** locking ***/
static void clk_prepare_lock(void)
{
@@ -1381,9 +1469,6 @@ static void __init clk_unprepare_unused_subtree(struct clk_core *core)
if (core->flags & CLK_IGNORE_UNUSED)
return;
- if (clk_pm_runtime_get(core))
- return;
-
if (clk_core_is_prepared(core)) {
trace_clk_unprepare(core);
if (core->ops->unprepare_unused)
@@ -1392,8 +1477,6 @@ static void __init clk_unprepare_unused_subtree(struct clk_core *core)
core->ops->unprepare(core->hw);
trace_clk_unprepare_complete(core);
}
-
- clk_pm_runtime_put(core);
}
static void __init clk_disable_unused_subtree(struct clk_core *core)
@@ -1409,9 +1492,6 @@ static void __init clk_disable_unused_subtree(struct clk_core *core)
if (core->flags & CLK_OPS_PARENT_ENABLE)
clk_core_prepare_enable(core->parent);
- if (clk_pm_runtime_get(core))
- goto unprepare_out;
-
flags = clk_enable_lock();
if (core->enable_count)
@@ -1436,8 +1516,6 @@ static void __init clk_disable_unused_subtree(struct clk_core *core)
unlock_out:
clk_enable_unlock(flags);
- clk_pm_runtime_put(core);
-unprepare_out:
if (core->flags & CLK_OPS_PARENT_ENABLE)
clk_core_disable_unprepare(core->parent);
}
@@ -1453,6 +1531,7 @@ __setup("clk_ignore_unused", clk_ignore_unused_setup);
static int __init clk_disable_unused(void)
{
struct clk_core *core;
+ int ret;
if (clk_ignore_unused) {
pr_warn("clk: Not disabling unused clocks\n");
@@ -1461,6 +1540,13 @@ static int __init clk_disable_unused(void)
pr_info("clk: Disabling unused clocks\n");
+ ret = clk_pm_runtime_get_all();
+ if (ret)
+ return ret;
+ /*
+ * Grab the prepare lock to keep the clk topology stable while iterating
+ * over clks.
+ */
clk_prepare_lock();
hlist_for_each_entry(core, &clk_root_list, child_node)
@@ -1477,6 +1563,8 @@ static int __init clk_disable_unused(void)
clk_prepare_unlock();
+ clk_pm_runtime_put_all();
+
return 0;
}
late_initcall_sync(clk_disable_unused);
@@ -3252,9 +3340,7 @@ static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
{
struct clk_core *child;
- clk_pm_runtime_get(c);
clk_summary_show_one(s, c, level);
- clk_pm_runtime_put(c);
hlist_for_each_entry(child, &c->children, child_node)
clk_summary_show_subtree(s, child, level + 1);
@@ -3264,11 +3350,15 @@ static int clk_summary_show(struct seq_file *s, void *data)
{
struct clk_core *c;
struct hlist_head **lists = s->private;
+ int ret;
seq_puts(s, " enable prepare protect duty hardware connection\n");
seq_puts(s, " clock count count count rate accuracy phase cycle enable consumer id\n");
seq_puts(s, "---------------------------------------------------------------------------------------------------------------------------------------------\n");
+ ret = clk_pm_runtime_get_all();
+ if (ret)
+ return ret;
clk_prepare_lock();
@@ -3277,6 +3367,7 @@ static int clk_summary_show(struct seq_file *s, void *data)
clk_summary_show_subtree(s, c, 0);
clk_prepare_unlock();
+ clk_pm_runtime_put_all();
return 0;
}
@@ -3324,8 +3415,14 @@ static int clk_dump_show(struct seq_file *s, void *data)
struct clk_core *c;
bool first_node = true;
struct hlist_head **lists = s->private;
+ int ret;
+
+ ret = clk_pm_runtime_get_all();
+ if (ret)
+ return ret;
seq_putc(s, '{');
+
clk_prepare_lock();
for (; *lists; lists++) {
@@ -3338,6 +3435,7 @@ static int clk_dump_show(struct seq_file *s, void *data)
}
clk_prepare_unlock();
+ clk_pm_runtime_put_all();
seq_puts(s, "}\n");
return 0;
@@ -3981,8 +4079,6 @@ static int __clk_core_init(struct clk_core *core)
}
clk_core_reparent_orphans_nolock();
-
- kref_init(&core->ref);
out:
clk_pm_runtime_put(core);
unlock:
@@ -4211,6 +4307,22 @@ static void clk_core_free_parent_map(struct clk_core *core)
kfree(core->parents);
}
+/* Free memory allocated for a struct clk_core */
+static void __clk_release(struct kref *ref)
+{
+ struct clk_core *core = container_of(ref, struct clk_core, ref);
+
+ if (core->rpm_enabled) {
+ mutex_lock(&clk_rpm_list_lock);
+ hlist_del(&core->rpm_node);
+ mutex_unlock(&clk_rpm_list_lock);
+ }
+
+ clk_core_free_parent_map(core);
+ kfree_const(core->name);
+ kfree(core);
+}
+
static struct clk *
__clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
{
@@ -4231,6 +4343,8 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
goto fail_out;
}
+ kref_init(&core->ref);
+
core->name = kstrdup_const(init->name, GFP_KERNEL);
if (!core->name) {
ret = -ENOMEM;
@@ -4243,9 +4357,8 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
}
core->ops = init->ops;
- if (dev && pm_runtime_enabled(dev))
- core->rpm_enabled = true;
core->dev = dev;
+ clk_pm_runtime_init(core);
core->of_node = np;
if (dev && dev->driver)
core->owner = dev->driver->owner;
@@ -4285,12 +4398,10 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
hw->clk = NULL;
fail_create_clk:
- clk_core_free_parent_map(core);
fail_parents:
fail_ops:
- kfree_const(core->name);
fail_name:
- kfree(core);
+ kref_put(&core->ref, __clk_release);
fail_out:
return ERR_PTR(ret);
}
@@ -4370,18 +4481,6 @@ int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
}
EXPORT_SYMBOL_GPL(of_clk_hw_register);
-/* Free memory allocated for a clock. */
-static void __clk_release(struct kref *ref)
-{
- struct clk_core *core = container_of(ref, struct clk_core, ref);
-
- lockdep_assert_held(&prepare_lock);
-
- clk_core_free_parent_map(core);
- kfree_const(core->name);
- kfree(core);
-}
-
/*
* Empty clk_ops for unregistered clocks. These are used temporarily
* after clk_unregister() was called on a clock and until last clock
@@ -4472,7 +4571,8 @@ void clk_unregister(struct clk *clk)
if (ops == &clk_nodrv_ops) {
pr_err("%s: unregistered clock: %s\n", __func__,
clk->core->name);
- goto unlock;
+ clk_prepare_unlock();
+ return;
}
/*
* Assign empty clock ops for consumers that might still hold
@@ -4506,11 +4606,10 @@ void clk_unregister(struct clk *clk)
if (clk->core->protect_count)
pr_warn("%s: unregistering protected clock: %s\n",
__func__, clk->core->name);
+ clk_prepare_unlock();
kref_put(&clk->core->ref, __clk_release);
free_clk(clk);
-unlock:
- clk_prepare_unlock();
}
EXPORT_SYMBOL_GPL(clk_unregister);
@@ -4669,13 +4768,11 @@ void __clk_put(struct clk *clk)
if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX)
clk_set_rate_range_nolock(clk, 0, ULONG_MAX);
- owner = clk->core->owner;
- kref_put(&clk->core->ref, __clk_release);
-
clk_prepare_unlock();
+ owner = clk->core->owner;
+ kref_put(&clk->core->ref, __clk_release);
module_put(owner);
-
free_clk(clk);
}
diff --git a/drivers/clk/mediatek/clk-mt7988-infracfg.c b/drivers/clk/mediatek/clk-mt7988-infracfg.c
index 449041f8abbc9a1cd97fa7d3807634653e677849..c8c023afe3e5adaf416ac413c7767812f7b97ab3 100644
--- a/drivers/clk/mediatek/clk-mt7988-infracfg.c
+++ b/drivers/clk/mediatek/clk-mt7988-infracfg.c
@@ -156,7 +156,7 @@ static const struct mtk_gate infra_clks[] = {
GATE_INFRA0(CLK_INFRA_PCIE_PERI_26M_CK_P1, "infra_pcie_peri_ck_26m_ck_p1",
"csw_infra_f26m_sel", 8),
GATE_INFRA0(CLK_INFRA_PCIE_PERI_26M_CK_P2, "infra_pcie_peri_ck_26m_ck_p2",
- "csw_infra_f26m_sel", 9),
+ "infra_pcie_peri_ck_26m_ck_p3", 9),
GATE_INFRA0(CLK_INFRA_PCIE_PERI_26M_CK_P3, "infra_pcie_peri_ck_26m_ck_p3",
"csw_infra_f26m_sel", 10),
/* INFRA1 */
diff --git a/drivers/clk/mediatek/clk-mtk.c b/drivers/clk/mediatek/clk-mtk.c
index 2e55368dc4d82095b5baceb7b744a9ed4b1350b4..bd37ab4d1a9bb3252ae54a2f3a3d3d241b1daa3a 100644
--- a/drivers/clk/mediatek/clk-mtk.c
+++ b/drivers/clk/mediatek/clk-mtk.c
@@ -13,6 +13,7 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include "clk-mtk.h"
@@ -494,6 +495,16 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev,
return IS_ERR(base) ? PTR_ERR(base) : -ENOMEM;
}
+
+ devm_pm_runtime_enable(&pdev->dev);
+ /*
+ * Do a pm_runtime_resume_and_get() to workaround a possible
+ * deadlock between clk_register() and the genpd framework.
+ */
+ r = pm_runtime_resume_and_get(&pdev->dev);
+ if (r)
+ return r;
+
/* Calculate how many clk_hw_onecell_data entries to allocate */
num_clks = mcd->num_clks + mcd->num_composite_clks;
num_clks += mcd->num_fixed_clks + mcd->num_factor_clks;
@@ -574,6 +585,8 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev,
goto unregister_clks;
}
+ pm_runtime_put(&pdev->dev);
+
return r;
unregister_clks:
@@ -604,6 +617,8 @@ static int __mtk_clk_simple_probe(struct platform_device *pdev,
free_base:
if (mcd->shared_io && base)
iounmap(base);
+
+ pm_runtime_put(&pdev->dev);
return r;
}
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 00623f4de5e195d5a4b880db633b1bfd335f34fc..0fa56d672532157290264c8dfa0a79dab94657bb 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -286,6 +286,11 @@ static inline int clk_rate_exclusive_get(struct clk *clk)
return 0;
}
+static inline int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk)
+{
+ return 0;
+}
+
static inline void clk_rate_exclusive_put(struct clk *clk) {}
#endif