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clk: Update req_rate on __clk_recalc_rates()

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Commit cb1b1dd962 ("clk: Set req_rate on reparenting") introduced a
new function, clk_core_update_orphan_child_rates(), that updates the
req_rate field on reparenting.

It turns out that that function will interfere with the clock notifying
done by __clk_recalc_rates(). This ends up reporting the new rate in
both the old_rate and new_rate fields of struct clk_notifier_data.

Since clk_core_update_orphan_child_rates() is basically
__clk_recalc_rates() without the notifiers, and with the req_rate field
update, we can drop clk_core_update_orphan_child_rates() entirely, and
make __clk_recalc_rates() update req_rate.

However, __clk_recalc_rates() is being called in several code paths:
when retrieving a rate (most likely through clk_get_rate()), when changing
parents (through clk_set_rate() or clk_hw_reparent()), or when updating
the orphan status (through clk_core_reparent_orphans_nolock(), called at
registration).

Updating req_rate on reparenting or initialisation makes sense, but we
shouldn't do it on clk_get_rate(). Thus an extra flag has been added to
update or not req_rate depending on the context.

Fixes: cb1b1dd962 ("clk: Set req_rate on reparenting")
Link: https://lore.kernel.org/linux-clk/0acc7217-762c-7c0d-45a0-55c384824ce4@samsung.com/
Link: https://lore.kernel.org/linux-clk/Y0QNSx+ZgqKSvPOC@sirena.org.uk/
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reported-by: Mark Brown <broonie@kernel.org>
Suggested-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20221010-rpi-clk-fixes-again-v1-1-d87ba82ac404@cerno.tech
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
This commit is contained in:
Maxime Ripard 2022-10-10 16:47:38 +02:00 committed by Stephen Boyd
parent 433fb8a611
commit 096f2a0c64
1 changed files with 11 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
drivers/clk/clk.c
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@ -1760,6 +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
@ -1769,7 +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;
@ -1783,6 +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
@ -1792,13 +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);
}
@ -1901,23 +1905,6 @@ static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
clk_core_update_orphan_status(child, is_orphan);
}
/*
* Update the orphan rate and req_rate of @core and all its children.
*/
static void clk_core_update_orphan_child_rates(struct clk_core *core)
{
struct clk_core *child;
unsigned long parent_rate = 0;
if (core->parent)
parent_rate = core->parent->rate;
core->rate = core->req_rate = clk_recalc(core, parent_rate);
hlist_for_each_entry(child, &core->children, child_node)
clk_core_update_orphan_child_rates(child);
}
static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
{
bool was_orphan = core->orphan;
@ -1987,8 +1974,6 @@ static struct clk_core *__clk_set_parent_before(struct clk_core *core,
clk_reparent(core, parent);
clk_enable_unlock(flags);
clk_core_update_orphan_child_rates(core);
return old_parent;
}
@ -2034,7 +2019,6 @@ static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
clk_reparent(core, old_parent);
clk_enable_unlock(flags);
clk_core_update_orphan_child_rates(core);
__clk_set_parent_after(core, old_parent, parent);
return ret;
@ -2658,9 +2642,8 @@ static void clk_core_reparent(struct clk_core *core,
struct clk_core *new_parent)
{
clk_reparent(core, new_parent);
clk_core_update_orphan_child_rates(core);
__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)
@ -2744,9 +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);
}
@ -3643,7 +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