Merge branch 'clk-rate-range' into clk-next

- Various clk rate range fixes
 - Drop clk rate range constraints on clk_put() (redux)

* clk-rate-range: (28 commits)
  clk: mediatek: clk-mux: Add .determine_rate() callback
  clk: tests: Add tests for notifiers
  clk: Update req_rate on __clk_recalc_rates()
  clk: tests: Add missing test case for ranges
  clk: qcom: clk-rcg2: Take clock boundaries into consideration for gfx3d
  clk: Introduce the clk_hw_get_rate_range function
  clk: Zero the clk_rate_request structure
  clk: Stop forwarding clk_rate_requests to the parent
  clk: Constify clk_has_parent()
  clk: Introduce clk_core_has_parent()
  clk: Switch from __clk_determine_rate to clk_core_round_rate_nolock
  clk: Add our request boundaries in clk_core_init_rate_req
  clk: Introduce clk_hw_init_rate_request()
  clk: Move clk_core_init_rate_req() from clk_core_round_rate_nolock() to its caller
  clk: Change clk_core_init_rate_req prototype
  clk: Set req_rate on reparenting
  clk: Take into account uncached clocks in clk_set_rate_range()
  clk: tests: Add some tests for orphan with multiple parents
  clk: tests: Add tests for mux with multiple parents
  clk: tests: Add tests for single parent mux
  ...

drivers/clk/at91/clk-generated.c

@@ -136,7 +136,6 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
 {
 	struct clk_generated *gck = to_clk_generated(hw);
 	struct clk_hw *parent = NULL;
-	struct clk_rate_request req_parent = *req;
 	long best_rate = -EINVAL;
 	unsigned long min_rate, parent_rate;
 	int best_diff = -1;
@@ -192,7 +191,9 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
 		goto end;
 
 	for (div = 1; div < GENERATED_MAX_DIV + 2; div++) {
-		req_parent.rate = req->rate * div;
+		struct clk_rate_request req_parent;
+
+		clk_hw_forward_rate_request(hw, req, parent, &req_parent, req->rate * div);
 		if (__clk_determine_rate(parent, &req_parent))
 			continue;
 		clk_generated_best_diff(req, parent, req_parent.rate, div,

drivers/clk/at91/clk-master.c

@@ -581,7 +581,6 @@ static int clk_sama7g5_master_determine_rate(struct clk_hw *hw,
 					     struct clk_rate_request *req)
 {
 	struct clk_master *master = to_clk_master(hw);
-	struct clk_rate_request req_parent = *req;
 	struct clk_hw *parent;
 	long best_rate = LONG_MIN, best_diff = LONG_MIN;
 	unsigned long parent_rate;
@@ -618,11 +617,15 @@ static int clk_sama7g5_master_determine_rate(struct clk_hw *hw,
 		goto end;
 
 	for (div = 0; div < MASTER_PRES_MAX + 1; div++) {
-		if (div == MASTER_PRES_MAX)
+		struct clk_rate_request req_parent;
-			req_parent.rate = req->rate * 3;
+		unsigned long req_rate;
-		else
-			req_parent.rate = req->rate << div;
 
+		if (div == MASTER_PRES_MAX)
+			req_rate = req->rate * 3;
+		else
+			req_rate = req->rate << div;
+
+		clk_hw_forward_rate_request(hw, req, parent, &req_parent, req_rate);
 		if (__clk_determine_rate(parent, &req_parent))
 			continue;
 

drivers/clk/at91/clk-peripheral.c

@@ -269,7 +269,6 @@ static int clk_sam9x5_peripheral_determine_rate(struct clk_hw *hw,
 {
 	struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
 	struct clk_hw *parent = clk_hw_get_parent(hw);
-	struct clk_rate_request req_parent = *req;
 	unsigned long parent_rate = clk_hw_get_rate(parent);
 	unsigned long tmp_rate;
 	long best_rate = LONG_MIN;
@@ -302,8 +301,9 @@ static int clk_sam9x5_peripheral_determine_rate(struct clk_hw *hw,
 		goto end;
 
 	for (shift = 0; shift <= PERIPHERAL_MAX_SHIFT; shift++) {
-		req_parent.rate = req->rate << shift;
+		struct clk_rate_request req_parent;
 
+		clk_hw_forward_rate_request(hw, req, parent, &req_parent, req->rate << shift);
 		if (__clk_determine_rate(parent, &req_parent))
 			continue;
 

drivers/clk/clk-composite.c

@@ -85,10 +85,11 @@ static int clk_composite_determine_rate(struct clk_hw *hw,
 		req->best_parent_hw = NULL;
 
 		if (clk_hw_get_flags(hw) & CLK_SET_RATE_NO_REPARENT) {
-			struct clk_rate_request tmp_req = *req;
+			struct clk_rate_request tmp_req;
 
 			parent = clk_hw_get_parent(mux_hw);
 
+			clk_hw_forward_rate_request(hw, req, parent, &tmp_req, req->rate);
 			ret = clk_composite_determine_rate_for_parent(rate_hw,
 								      &tmp_req,
 								      parent,
@@ -104,12 +105,13 @@ static int clk_composite_determine_rate(struct clk_hw *hw,
 		}
 
 		for (i = 0; i < clk_hw_get_num_parents(mux_hw); i++) {
-			struct clk_rate_request tmp_req = *req;
+			struct clk_rate_request tmp_req;
 
 			parent = clk_hw_get_parent_by_index(mux_hw, i);
 			if (!parent)
 				continue;
 
+			clk_hw_forward_rate_request(hw, req, parent, &tmp_req, req->rate);
 			ret = clk_composite_determine_rate_for_parent(rate_hw,
 								      &tmp_req,
 								      parent,

drivers/clk/clk-divider.c

@@ -386,13 +386,13 @@ long divider_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
 			       const struct clk_div_table *table,
 			       u8 width, unsigned long flags)
 {
-	struct clk_rate_request req = {
+	struct clk_rate_request req;
-		.rate = rate,
-		.best_parent_rate = *prate,
-		.best_parent_hw = parent,
-	};
 	int ret;
 
+	clk_hw_init_rate_request(hw, &req, rate);
+	req.best_parent_rate = *prate;
+	req.best_parent_hw = parent;
+
 	ret = divider_determine_rate(hw, &req, table, width, flags);
 	if (ret)
 		return ret;
@@ -408,13 +408,13 @@ long divider_ro_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
 				  const struct clk_div_table *table, u8 width,
 				  unsigned long flags, unsigned int val)
 {
-	struct clk_rate_request req = {
+	struct clk_rate_request req;
-		.rate = rate,
-		.best_parent_rate = *prate,
-		.best_parent_hw = parent,
-	};
 	int ret;
 
+	clk_hw_init_rate_request(hw, &req, rate);
+	req.best_parent_rate = *prate;
+	req.best_parent_hw = parent;
+
 	ret = divider_ro_determine_rate(hw, &req, table, width, flags, val);
 	if (ret)
 		return ret;

drivers/clk/clk.c

@@ -536,6 +536,53 @@ static bool mux_is_better_rate(unsigned long rate, unsigned long now,
 	return now <= rate && now > best;
 }
 
+static void clk_core_init_rate_req(struct clk_core * const core,
+				   struct clk_rate_request *req,
+				   unsigned long rate);
+
+static int clk_core_round_rate_nolock(struct clk_core *core,
+				      struct clk_rate_request *req);
+
+static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *parent)
+{
+	struct clk_core *tmp;
+	unsigned int i;
+
+	/* Optimize for the case where the parent is already the parent. */
+	if (core->parent == parent)
+		return true;
+
+	for (i = 0; i < core->num_parents; i++) {
+		tmp = clk_core_get_parent_by_index(core, i);
+		if (!tmp)
+			continue;
+
+		if (tmp == parent)
+			return true;
+	}
+
+	return false;
+}
+
+static void
+clk_core_forward_rate_req(struct clk_core *core,
+			  const struct clk_rate_request *old_req,
+			  struct clk_core *parent,
+			  struct clk_rate_request *req,
+			  unsigned long parent_rate)
+{
+	if (WARN_ON(!clk_core_has_parent(core, parent)))
+		return;
+
+	clk_core_init_rate_req(parent, req, parent_rate);
+
+	if (req->min_rate < old_req->min_rate)
+		req->min_rate = old_req->min_rate;
+
+	if (req->max_rate > old_req->max_rate)
+		req->max_rate = old_req->max_rate;
+}
+
 int clk_mux_determine_rate_flags(struct clk_hw *hw,
 				 struct clk_rate_request *req,
 				 unsigned long flags)
@@ -543,14 +590,20 @@ int clk_mux_determine_rate_flags(struct clk_hw *hw,
 	struct clk_core *core = hw->core, *parent, *best_parent = NULL;
 	int i, num_parents, ret;
 	unsigned long best = 0;
-	struct clk_rate_request parent_req = *req;
 
 	/* if NO_REPARENT flag set, pass through to current parent */
 	if (core->flags & CLK_SET_RATE_NO_REPARENT) {
 		parent = core->parent;
 		if (core->flags & CLK_SET_RATE_PARENT) {
-			ret = __clk_determine_rate(parent ? parent->hw : NULL,
+			struct clk_rate_request parent_req;
-						   &parent_req);
+
+			if (!parent) {
+				req->rate = 0;
+				return 0;
+			}
+
+			clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
+			ret = clk_core_round_rate_nolock(parent, &parent_req);
 			if (ret)
 				return ret;
 
@@ -567,23 +620,29 @@ int clk_mux_determine_rate_flags(struct clk_hw *hw,
 	/* find the parent that can provide the fastest rate <= rate */
 	num_parents = core->num_parents;
 	for (i = 0; i < num_parents; i++) {
+		unsigned long parent_rate;
+
 		parent = clk_core_get_parent_by_index(core, i);
 		if (!parent)
 			continue;
 
 		if (core->flags & CLK_SET_RATE_PARENT) {
-			parent_req = *req;
+			struct clk_rate_request parent_req;
-			ret = __clk_determine_rate(parent->hw, &parent_req);
+
+			clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
+			ret = clk_core_round_rate_nolock(parent, &parent_req);
 			if (ret)
 				continue;
+
+			parent_rate = parent_req.rate;
 		} else {
-			parent_req.rate = clk_core_get_rate_nolock(parent);
+			parent_rate = clk_core_get_rate_nolock(parent);
 		}
 
-		if (mux_is_better_rate(req->rate, parent_req.rate,
+		if (mux_is_better_rate(req->rate, parent_rate,
 				       best, flags)) {
 			best_parent = parent;
-			best = parent_req.rate;
+			best = parent_rate;
 		}
 	}
 
@@ -625,6 +684,22 @@ static void clk_core_get_boundaries(struct clk_core *core,
 		*max_rate = min(*max_rate, clk_user->max_rate);
 }
 
+/*
+ * clk_hw_get_rate_range() - returns the clock rate range for a hw clk
+ * @hw: the hw clk we want to get the range from
+ * @min_rate: pointer to the variable that will hold the minimum
+ * @max_rate: pointer to the variable that will hold the maximum
+ *
+ * Fills the @min_rate and @max_rate variables with the minimum and
+ * maximum that clock can reach.
+ */
+void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate,
+			   unsigned long *max_rate)
+{
+	clk_core_get_boundaries(hw->core, min_rate, max_rate);
+}
+EXPORT_SYMBOL_GPL(clk_hw_get_rate_range);
+
 static bool clk_core_check_boundaries(struct clk_core *core,
 				      unsigned long min_rate,
 				      unsigned long max_rate)
@@ -1341,7 +1416,19 @@ static int clk_core_determine_round_nolock(struct clk_core *core,
 	if (!core)
 		return 0;
 
-	req->rate = clamp(req->rate, req->min_rate, req->max_rate);
+	/*
+	 * Some clock providers hand-craft their clk_rate_requests and
+	 * might not fill min_rate and max_rate.
+	 *
+	 * If it's the case, clamping the rate is equivalent to setting
+	 * the rate to 0 which is bad. Skip the clamping but complain so
+	 * that it gets fixed, hopefully.
+	 */
+	if (!req->min_rate && !req->max_rate)
+		pr_warn("%s: %s: clk_rate_request has initialized min or max rate.\n",
+			__func__, core->name);
+	else
+		req->rate = clamp(req->rate, req->min_rate, req->max_rate);
 
 	/*
 	 * At this point, core protection will be disabled
@@ -1368,13 +1455,19 @@ static int clk_core_determine_round_nolock(struct clk_core *core,
 }
 
 static void clk_core_init_rate_req(struct clk_core * const core,
-				   struct clk_rate_request *req)
+				   struct clk_rate_request *req,
+				   unsigned long rate)
 {
 	struct clk_core *parent;
 
 	if (WARN_ON(!core || !req))
 		return;
 
+	memset(req, 0, sizeof(*req));
+
+	req->rate = rate;
+	clk_core_get_boundaries(core, &req->min_rate, &req->max_rate);
+
 	parent = core->parent;
 	if (parent) {
 		req->best_parent_hw = parent->hw;
@@ -1385,6 +1478,51 @@ static void clk_core_init_rate_req(struct clk_core * const core,
 	}
 }
 
+/**
+ * clk_hw_init_rate_request - Initializes a clk_rate_request
+ * @hw: the clk for which we want to submit a rate request
+ * @req: the clk_rate_request structure we want to initialise
+ * @rate: the rate which is to be requested
+ *
+ * Initializes a clk_rate_request structure to submit to
+ * __clk_determine_rate() or similar functions.
+ */
+void clk_hw_init_rate_request(const struct clk_hw *hw,
+			      struct clk_rate_request *req,
+			      unsigned long rate)
+{
+	if (WARN_ON(!hw || !req))
+		return;
+
+	clk_core_init_rate_req(hw->core, req, rate);
+}
+EXPORT_SYMBOL_GPL(clk_hw_init_rate_request);
+
+/**
+ * clk_hw_forward_rate_request - Forwards a clk_rate_request to a clock's parent
+ * @hw: the original clock that got the rate request
+ * @old_req: the original clk_rate_request structure we want to forward
+ * @parent: the clk we want to forward @old_req to
+ * @req: the clk_rate_request structure we want to initialise
+ * @parent_rate: The rate which is to be requested to @parent
+ *
+ * Initializes a clk_rate_request structure to submit to a clock parent
+ * in __clk_determine_rate() or similar functions.
+ */
+void clk_hw_forward_rate_request(const struct clk_hw *hw,
+				 const struct clk_rate_request *old_req,
+				 const struct clk_hw *parent,
+				 struct clk_rate_request *req,
+				 unsigned long parent_rate)
+{
+	if (WARN_ON(!hw || !old_req || !parent || !req))
+		return;
+
+	clk_core_forward_rate_req(hw->core, old_req,
+				  parent->core, req,
+				  parent_rate);
+}
+
 static bool clk_core_can_round(struct clk_core * const core)
 {
 	return core->ops->determine_rate || core->ops->round_rate;
@@ -1393,6 +1531,8 @@ static bool clk_core_can_round(struct clk_core * const core)
 static int clk_core_round_rate_nolock(struct clk_core *core,
 				      struct clk_rate_request *req)
 {
+	int ret;
+
 	lockdep_assert_held(&prepare_lock);
 
 	if (!core) {
@@ -1400,12 +1540,22 @@ static int clk_core_round_rate_nolock(struct clk_core *core,
 		return 0;
 	}
 
-	clk_core_init_rate_req(core, req);
-
 	if (clk_core_can_round(core))
 		return clk_core_determine_round_nolock(core, req);
-	else if (core->flags & CLK_SET_RATE_PARENT)
+
-		return clk_core_round_rate_nolock(core->parent, req);
+	if (core->flags & CLK_SET_RATE_PARENT) {
+		struct clk_rate_request parent_req;
+
+		clk_core_forward_rate_req(core, req, core->parent, &parent_req, req->rate);
+		ret = clk_core_round_rate_nolock(core->parent, &parent_req);
+		if (ret)
+			return ret;
+
+		req->best_parent_rate = parent_req.rate;
+		req->rate = parent_req.rate;
+
+		return 0;
+	}
 
 	req->rate = core->rate;
 	return 0;
@@ -1449,8 +1599,7 @@ unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
 	int ret;
 	struct clk_rate_request req;
 
-	clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
+	clk_core_init_rate_req(hw->core, &req, rate);
-	req.rate = rate;
 
 	ret = clk_core_round_rate_nolock(hw->core, &req);
 	if (ret)
@@ -1482,8 +1631,7 @@ long clk_round_rate(struct clk *clk, unsigned long rate)
 	if (clk->exclusive_count)
 		clk_core_rate_unprotect(clk->core);
 
-	clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
+	clk_core_init_rate_req(clk->core, &req, rate);
-	req.rate = rate;
 
 	ret = clk_core_round_rate_nolock(clk->core, &req);
 
@@ -1612,6 +1760,7 @@ static unsigned long clk_recalc(struct clk_core *core,
 /**
  * __clk_recalc_rates
  * @core: first clk in the subtree
+ * @update_req: Whether req_rate should be updated with the new rate
  * @msg: notification type (see include/linux/clk.h)
  *
  * Walks the subtree of clks starting with clk and recalculates rates as it
@@ -1621,7 +1770,8 @@ static unsigned long clk_recalc(struct clk_core *core,
  * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
  * if necessary.
  */
-static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
+static void __clk_recalc_rates(struct clk_core *core, bool update_req,
+			       unsigned long msg)
 {
 	unsigned long old_rate;
 	unsigned long parent_rate = 0;
@@ -1635,6 +1785,8 @@ static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
 		parent_rate = core->parent->rate;
 
 	core->rate = clk_recalc(core, parent_rate);
+	if (update_req)
+		core->req_rate = core->rate;
 
 	/*
 	 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
@@ -1644,13 +1796,13 @@ static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
 		__clk_notify(core, msg, old_rate, core->rate);
 
 	hlist_for_each_entry(child, &core->children, child_node)
-		__clk_recalc_rates(child, msg);
+		__clk_recalc_rates(child, update_req, msg);
 }
 
 static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
 {
 	if (core && (core->flags & CLK_GET_RATE_NOCACHE))
-		__clk_recalc_rates(core, 0);
+		__clk_recalc_rates(core, false, 0);
 
 	return clk_core_get_rate_nolock(core);
 }
@@ -1660,8 +1812,9 @@ static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
  * @clk: the clk whose rate is being returned
  *
  * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
- * is set, which means a recalc_rate will be issued.
+ * is set, which means a recalc_rate will be issued. Can be called regardless of
- * If clk is NULL then returns 0.
+ * the clock enabledness. If clk is NULL, or if an error occurred, then returns
+ * 0.
  */
 unsigned long clk_get_rate(struct clk *clk)
 {
@@ -1865,6 +2018,7 @@ static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
 		flags = clk_enable_lock();
 		clk_reparent(core, old_parent);
 		clk_enable_unlock(flags);
+
 		__clk_set_parent_after(core, old_parent, parent);
 
 		return ret;
@@ -1970,11 +2124,7 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *core,
 	if (clk_core_can_round(core)) {
 		struct clk_rate_request req;
 
-		req.rate = rate;
+		clk_core_init_rate_req(core, &req, rate);
-		req.min_rate = min_rate;
-		req.max_rate = max_rate;
-
-		clk_core_init_rate_req(core, &req);
 
 		ret = clk_core_determine_round_nolock(core, &req);
 		if (ret < 0)
@@ -2173,8 +2323,7 @@ static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
 	if (cnt < 0)
 		return cnt;
 
-	clk_core_get_boundaries(core, &req.min_rate, &req.max_rate);
+	clk_core_init_rate_req(core, &req, req_rate);
-	req.rate = req_rate;
 
 	ret = clk_core_round_rate_nolock(core, &req);
 
@@ -2325,19 +2474,15 @@ int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
 }
 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
 
-/**
+static int clk_set_rate_range_nolock(struct clk *clk,
- * clk_set_rate_range - set a rate range for a clock source
+				     unsigned long min,
- * @clk: clock source
+				     unsigned long max)
- * @min: desired minimum clock rate in Hz, inclusive
- * @max: desired maximum clock rate in Hz, inclusive
- *
- * Returns success (0) or negative errno.
- */
-int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
 {
 	int ret = 0;
 	unsigned long old_min, old_max, rate;
 
+	lockdep_assert_held(&prepare_lock);
+
 	if (!clk)
 		return 0;
 
@@ -2350,8 +2495,6 @@ int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
 		return -EINVAL;
 	}
 
-	clk_prepare_lock();
-
 	if (clk->exclusive_count)
 		clk_core_rate_unprotect(clk->core);
 
@@ -2366,6 +2509,10 @@ int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
 		goto out;
 	}
 
+	rate = clk->core->req_rate;
+	if (clk->core->flags & CLK_GET_RATE_NOCACHE)
+		rate = clk_core_get_rate_recalc(clk->core);
+
 	/*
 	 * Since the boundaries have been changed, let's give the
 	 * opportunity to the provider to adjust the clock rate based on
@@ -2383,7 +2530,7 @@ int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
 	 * - the determine_rate() callback does not really check for
 	 *   this corner case when determining the rate
 	 */
-	rate = clamp(clk->core->req_rate, min, max);
+	rate = clamp(rate, min, max);
 	ret = clk_core_set_rate_nolock(clk->core, rate);
 	if (ret) {
 		/* rollback the changes */
@@ -2395,6 +2542,28 @@ out:
 	if (clk->exclusive_count)
 		clk_core_rate_protect(clk->core);
 
+	return ret;
+}
+
+/**
+ * clk_set_rate_range - set a rate range for a clock source
+ * @clk: clock source
+ * @min: desired minimum clock rate in Hz, inclusive
+ * @max: desired maximum clock rate in Hz, inclusive
+ *
+ * Return: 0 for success or negative errno on failure.
+ */
+int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
+{
+	int ret;
+
+	if (!clk)
+		return 0;
+
+	clk_prepare_lock();
+
+	ret = clk_set_rate_range_nolock(clk, min, max);
+
 	clk_prepare_unlock();
 
 	return ret;
@@ -2474,7 +2643,7 @@ static void clk_core_reparent(struct clk_core *core,
 {
 	clk_reparent(core, new_parent);
 	__clk_recalc_accuracies(core);
-	__clk_recalc_rates(core, POST_RATE_CHANGE);
+	__clk_recalc_rates(core, true, POST_RATE_CHANGE);
 }
 
 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
@@ -2495,27 +2664,13 @@ void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
  *
  * Returns true if @parent is a possible parent for @clk, false otherwise.
  */
-bool clk_has_parent(struct clk *clk, struct clk *parent)
+bool clk_has_parent(const struct clk *clk, const struct clk *parent)
 {
-	struct clk_core *core, *parent_core;
-	int i;
-
 	/* NULL clocks should be nops, so return success if either is NULL. */
 	if (!clk || !parent)
 		return true;
 
-	core = clk->core;
+	return clk_core_has_parent(clk->core, parent->core);
-	parent_core = parent->core;
-
-	/* Optimize for the case where the parent is already the parent. */
-	if (core->parent == parent_core)
-		return true;
-
-	for (i = 0; i < core->num_parents; i++)
-		if (!strcmp(core->parents[i].name, parent_core->name))
-			return true;
-
-	return false;
 }
 EXPORT_SYMBOL_GPL(clk_has_parent);
 
@@ -2572,9 +2727,9 @@ static int clk_core_set_parent_nolock(struct clk_core *core,
 
 	/* propagate rate an accuracy recalculation accordingly */
 	if (ret) {
-		__clk_recalc_rates(core, ABORT_RATE_CHANGE);
+		__clk_recalc_rates(core, true, ABORT_RATE_CHANGE);
 	} else {
-		__clk_recalc_rates(core, POST_RATE_CHANGE);
+		__clk_recalc_rates(core, true, POST_RATE_CHANGE);
 		__clk_recalc_accuracies(core);
 	}
 
@@ -3471,7 +3626,7 @@ static void clk_core_reparent_orphans_nolock(void)
 			__clk_set_parent_before(orphan, parent);
 			__clk_set_parent_after(orphan, parent, NULL);
 			__clk_recalc_accuracies(orphan);
-			__clk_recalc_rates(orphan, 0);
+			__clk_recalc_rates(orphan, true, 0);
 
 			/*
 			 * __clk_init_parent() will set the initial req_rate to
@@ -4347,9 +4502,10 @@ void __clk_put(struct clk *clk)
 	}
 
 	hlist_del(&clk->clks_node);
-	if (clk->min_rate > clk->core->req_rate ||
+
-	    clk->max_rate < clk->core->req_rate)
+	/* If we had any boundaries on that clock, let's drop them. */
-		clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
+	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);

drivers/clk/mediatek/clk-mux.c

@@ -129,9 +129,18 @@ static int mtk_clk_mux_set_parent_setclr_lock(struct clk_hw *hw, u8 index)
 	return 0;
 }
 
+static int mtk_clk_mux_determine_rate(struct clk_hw *hw,
+				      struct clk_rate_request *req)
+{
+	struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+
+	return clk_mux_determine_rate_flags(hw, req, mux->data->flags);
+}
+
 const struct clk_ops mtk_mux_clr_set_upd_ops = {
 	.get_parent = mtk_clk_mux_get_parent,
 	.set_parent = mtk_clk_mux_set_parent_setclr_lock,
+	.determine_rate = mtk_clk_mux_determine_rate,
 };
 EXPORT_SYMBOL_GPL(mtk_mux_clr_set_upd_ops);
 
@@ -141,6 +150,7 @@ const struct clk_ops mtk_mux_gate_clr_set_upd_ops  = {
 	.is_enabled = mtk_clk_mux_is_enabled,
 	.get_parent = mtk_clk_mux_get_parent,
 	.set_parent = mtk_clk_mux_set_parent_setclr_lock,
+	.determine_rate = mtk_clk_mux_determine_rate,
 };
 EXPORT_SYMBOL_GPL(mtk_mux_gate_clr_set_upd_ops);
 

drivers/clk/qcom/clk-rcg2.c

@@ -915,6 +915,15 @@ static int clk_gfx3d_determine_rate(struct clk_hw *hw,
 		req->best_parent_hw = p2;
 	}
 
+	clk_hw_get_rate_range(req->best_parent_hw,
+			      &parent_req.min_rate, &parent_req.max_rate);
+
+	if (req->min_rate > parent_req.min_rate)
+		parent_req.min_rate = req->min_rate;
+
+	if (req->max_rate < parent_req.max_rate)
+		parent_req.max_rate = req->max_rate;
+
 	ret = __clk_determine_rate(req->best_parent_hw, &parent_req);
 	if (ret)
 		return ret;

include/linux/clk-provider.h

@@ -42,6 +42,8 @@ struct dentry;
  * struct clk_rate_request - Structure encoding the clk constraints that
  * a clock user might require.
  *
+ * Should be initialized by calling clk_hw_init_rate_request().
+ *
  * @rate:		Requested clock rate. This field will be adjusted by
  *			clock drivers according to hardware capabilities.
  * @min_rate:		Minimum rate imposed by clk users.
@@ -60,6 +62,15 @@ struct clk_rate_request {
 	struct clk_hw *best_parent_hw;
 };
 
+void clk_hw_init_rate_request(const struct clk_hw *hw,
+			      struct clk_rate_request *req,
+			      unsigned long rate);
+void clk_hw_forward_rate_request(const struct clk_hw *core,
+				 const struct clk_rate_request *old_req,
+				 const struct clk_hw *parent,
+				 struct clk_rate_request *req,
+				 unsigned long parent_rate);
+
 /**
  * struct clk_duty - Struture encoding the duty cycle ratio of a clock
  *
@@ -118,8 +129,9 @@ struct clk_duty {
  *
  * @recalc_rate	Recalculate the rate of this clock, by querying hardware. The
  *		parent rate is an input parameter.  It is up to the caller to
- *		ensure that the prepare_mutex is held across this call.
+ *		ensure that the prepare_mutex is held across this call. If the
- *		Returns the calculated rate.  Optional, but recommended - if
+ *		driver cannot figure out a rate for this clock, it must return
+ *		0. Returns the calculated rate. Optional, but recommended - if
  *		this op is not set then clock rate will be initialized to 0.
  *
  * @round_rate:	Given a target rate as input, returns the closest rate actually
@@ -1303,6 +1315,8 @@ int clk_mux_determine_rate_flags(struct clk_hw *hw,
 				 struct clk_rate_request *req,
 				 unsigned long flags);
 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent);
+void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate,
+			   unsigned long *max_rate);
 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
 			   unsigned long max_rate);
 

include/linux/clk.h

@@ -799,7 +799,7 @@ int clk_set_rate_exclusive(struct clk *clk, unsigned long rate);
  *
  * Returns true if @parent is a possible parent for @clk, false otherwise.
  */
-bool clk_has_parent(struct clk *clk, struct clk *parent);
+bool clk_has_parent(const struct clk *clk, const struct clk *parent);
 
 /**
  * clk_set_rate_range - set a rate range for a clock source