Messages in this thread Patch in this message | | | From | Benjamin Bara <> | Date | Mon, 02 Oct 2023 11:23:32 +0200 | Subject | [PATCH RFC 1/4] clk: only set req_rate if it is set by consumer |
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From: Benjamin Bara <benjamin.bara@skidata.com>
Currently, the req_rate is set during initialization and during re-parenting. Therefore, it is not clear whether the req_rate is really required by a consumer or just set by accident. Fix this by only setting the req_rate when it is really required (clk_set_rate() is called by consumer).
Signed-off-by: Benjamin Bara <benjamin.bara@skidata.com> --- drivers/clk/clk.c | 37 ++++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 13 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index c249f9791ae8..82f954121e4d 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -24,6 +24,8 @@ #include "clk.h" +#define CLK_RATE_UNSET -1UL + static DEFINE_SPINLOCK(enable_lock); static DEFINE_MUTEX(prepare_lock); @@ -1832,7 +1834,6 @@ 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 @@ -1842,8 +1843,7 @@ 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, bool update_req, - unsigned long msg) +static void __clk_recalc_rates(struct clk_core *core, unsigned long msg) { unsigned long old_rate; unsigned long parent_rate = 0; @@ -1857,8 +1857,6 @@ static void __clk_recalc_rates(struct clk_core *core, bool update_req, 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 @@ -1868,13 +1866,13 @@ static void __clk_recalc_rates(struct clk_core *core, bool update_req, __clk_notify(core, msg, old_rate, core->rate); hlist_for_each_entry(child, &core->children, child_node) - __clk_recalc_rates(child, update_req, msg); + __clk_recalc_rates(child, 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, false, 0); + __clk_recalc_rates(core, 0); return clk_core_get_rate_nolock(core); } @@ -2455,7 +2453,6 @@ static int clk_core_set_rate_nolock(struct clk_core *core, /* change the rates */ clk_change_rate(top); - core->req_rate = req_rate; err: clk_pm_runtime_put(core); @@ -2485,6 +2482,7 @@ static int clk_core_set_rate_nolock(struct clk_core *core, */ int clk_set_rate(struct clk *clk, unsigned long rate) { + unsigned long old_req_rate; int ret; if (!clk) @@ -2493,6 +2491,9 @@ int clk_set_rate(struct clk *clk, unsigned long rate) /* prevent racing with updates to the clock topology */ clk_prepare_lock(); + old_req_rate = clk->core->req_rate; + clk->core->req_rate = rate; + if (clk->exclusive_count) clk_core_rate_unprotect(clk->core); @@ -2501,6 +2502,9 @@ int clk_set_rate(struct clk *clk, unsigned long rate) if (clk->exclusive_count) clk_core_rate_protect(clk->core); + if (ret) + clk->core->req_rate = old_req_rate; + clk_prepare_unlock(); return ret; @@ -2528,6 +2532,7 @@ EXPORT_SYMBOL_GPL(clk_set_rate); */ int clk_set_rate_exclusive(struct clk *clk, unsigned long rate) { + unsigned long old_req_rate; int ret; if (!clk) @@ -2536,6 +2541,9 @@ int clk_set_rate_exclusive(struct clk *clk, unsigned long rate) /* prevent racing with updates to the clock topology */ clk_prepare_lock(); + old_req_rate = clk->core->req_rate; + clk->core->req_rate = rate; + /* * The temporary protection removal is not here, on purpose * This function is meant to be used instead of clk_rate_protect, @@ -2546,6 +2554,8 @@ int clk_set_rate_exclusive(struct clk *clk, unsigned long rate) if (!ret) { clk_core_rate_protect(clk->core); clk->exclusive_count++; + } else { + clk->core->req_rate = old_req_rate; } clk_prepare_unlock(); @@ -2723,7 +2733,7 @@ static void clk_core_reparent(struct clk_core *core, { clk_reparent(core, new_parent); __clk_recalc_accuracies(core); - __clk_recalc_rates(core, true, POST_RATE_CHANGE); + __clk_recalc_rates(core, POST_RATE_CHANGE); } void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent) @@ -2807,9 +2817,9 @@ static int clk_core_set_parent_nolock(struct clk_core *core, /* propagate rate an accuracy recalculation accordingly */ if (ret) { - __clk_recalc_rates(core, true, ABORT_RATE_CHANGE); + __clk_recalc_rates(core, ABORT_RATE_CHANGE); } else { - __clk_recalc_rates(core, true, POST_RATE_CHANGE); + __clk_recalc_rates(core, POST_RATE_CHANGE); __clk_recalc_accuracies(core); } @@ -3706,7 +3716,7 @@ 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, true, 0); + __clk_recalc_rates(orphan, 0); /* * __clk_init_parent() will set the initial req_rate to @@ -3888,7 +3898,8 @@ static int __clk_core_init(struct clk_core *core) rate = parent->rate; else rate = 0; - core->rate = core->req_rate = rate; + core->rate = rate; + core->req_rate = CLK_RATE_UNSET; /* * Enable CLK_IS_CRITICAL clocks so newly added critical clocks -- 2.34.1
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