| Message ID | 20220706150411.708213-1-abel.vesa@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC,1/2] clk: Add generic sync_state callback for disabling unused clocks | expand |
On 22-07-06 18:04:10, Abel Vesa wrote: > There are unused clocks that need to stay enabled on clk_disable_unused, > but rather should be disabled later on on sync_state. Provide a generic > sync_state callback for the clock providers that register such clocks. > Then, use the same mechanism as clk_disable_unused from that generic > callback, but pass the device to make sure only the clocks belonging to > the current clock provider get disabled, if unused. Also, during the > default clk_disable_unused, if the driver that registered the clock has > the generic clk_sync_state_disable_unused callback set for sync_state, > leave its clocks enabled. > > Signed-off-by: Abel Vesa <abel.vesa@linaro.org> Gentle ping. > --- > drivers/clk/clk.c | 67 +++++++++++++++++++++++++++--------- > include/linux/clk-provider.h | 1 + > 2 files changed, 52 insertions(+), 16 deletions(-) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index 7fc191c15507..ea55806505c0 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -1218,19 +1218,31 @@ static void clk_core_disable_unprepare(struct clk_core *core) > clk_core_unprepare_lock(core); > } > > -static void __init clk_unprepare_unused_subtree(struct clk_core *core) > +static void clk_unprepare_unused_subtree(struct clk_core *core, > + struct device *dev) > { > struct clk_core *child; > > lockdep_assert_held(&prepare_lock); > > hlist_for_each_entry(child, &core->children, child_node) > - clk_unprepare_unused_subtree(child); > + clk_unprepare_unused_subtree(child, dev); > + > + if (dev && core->dev != dev) > + return; > + > + /* > + * clock will be unprepared on sync_state, > + * so leave as is on clk_disable_unused > + */ > + if (!dev && dev_has_sync_state(core->dev) && > + core->dev->driver->sync_state == clk_sync_state_disable_unused) > + return; > > if (core->prepare_count) > return; > > - if (core->flags & CLK_IGNORE_UNUSED) > + if (!dev && core->flags & CLK_IGNORE_UNUSED) > return; > > if (clk_pm_runtime_get(core)) > @@ -1248,7 +1260,8 @@ static void __init clk_unprepare_unused_subtree(struct clk_core *core) > clk_pm_runtime_put(core); > } > > -static void __init clk_disable_unused_subtree(struct clk_core *core) > +static void clk_disable_unused_subtree(struct clk_core *core, > + struct device *dev) > { > struct clk_core *child; > unsigned long flags; > @@ -1256,7 +1269,18 @@ static void __init clk_disable_unused_subtree(struct clk_core *core) > lockdep_assert_held(&prepare_lock); > > hlist_for_each_entry(child, &core->children, child_node) > - clk_disable_unused_subtree(child); > + clk_disable_unused_subtree(child, dev); > + > + if (dev && core->dev != dev) > + return; > + > + /* > + * clock will be disabled on sync_state, > + * so leave as is on clk_disable_unused > + */ > + if (!dev && dev_has_sync_state(core->dev) && > + core->dev->driver->sync_state == clk_sync_state_disable_unused) > + return; > > if (core->flags & CLK_OPS_PARENT_ENABLE) > clk_core_prepare_enable(core->parent); > @@ -1269,7 +1293,7 @@ static void __init clk_disable_unused_subtree(struct clk_core *core) > if (core->enable_count) > goto unlock_out; > > - if (core->flags & CLK_IGNORE_UNUSED) > + if (!dev && core->flags & CLK_IGNORE_UNUSED) > goto unlock_out; > > /* > @@ -1302,35 +1326,46 @@ static int __init clk_ignore_unused_setup(char *__unused) > } > __setup("clk_ignore_unused", clk_ignore_unused_setup); > > -static int __init clk_disable_unused(void) > +static void __clk_disable_unused(struct device *dev) > { > struct clk_core *core; > > - if (clk_ignore_unused) { > - pr_warn("clk: Not disabling unused clocks\n"); > - return 0; > - } > - > clk_prepare_lock(); > > hlist_for_each_entry(core, &clk_root_list, child_node) > - clk_disable_unused_subtree(core); > + clk_disable_unused_subtree(core, dev); > > hlist_for_each_entry(core, &clk_orphan_list, child_node) > - clk_disable_unused_subtree(core); > + clk_disable_unused_subtree(core, dev); > > hlist_for_each_entry(core, &clk_root_list, child_node) > - clk_unprepare_unused_subtree(core); > + clk_unprepare_unused_subtree(core, dev); > > hlist_for_each_entry(core, &clk_orphan_list, child_node) > - clk_unprepare_unused_subtree(core); > + clk_unprepare_unused_subtree(core, dev); > > clk_prepare_unlock(); > +} > + > +static int __init clk_disable_unused(void) > +{ > + if (clk_ignore_unused) { > + pr_warn("clk: Not disabling unused clocks\n"); > + return 0; > + } > + > + __clk_disable_unused(NULL); > > return 0; > } > late_initcall_sync(clk_disable_unused); > > +void clk_sync_state_disable_unused(struct device *dev) > +{ > + __clk_disable_unused(dev); > +} > +EXPORT_SYMBOL_GPL(clk_sync_state_disable_unused); > + > static int clk_core_determine_round_nolock(struct clk_core *core, > struct clk_rate_request *req) > { > diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h > index 72d937c03a3e..5d3ed2b14f2c 100644 > --- a/include/linux/clk-provider.h > +++ b/include/linux/clk-provider.h > @@ -679,6 +679,7 @@ struct clk *clk_register_divider_table(struct device *dev, const char *name, > void __iomem *reg, u8 shift, u8 width, > u8 clk_divider_flags, const struct clk_div_table *table, > spinlock_t *lock); > +void clk_sync_state_disable_unused(struct device *dev); > /** > * clk_register_divider - register a divider clock with the clock framework > * @dev: device registering this clock > -- > 2.34.3 >
On Wed, Jul 06, 2022 at 06:04:10PM +0300, Abel Vesa wrote: > There are unused clocks that need to stay enabled on clk_disable_unused, > but rather should be disabled later on on sync_state. Provide a generic > sync_state callback for the clock providers that register such clocks. > Then, use the same mechanism as clk_disable_unused from that generic > callback, but pass the device to make sure only the clocks belonging to > the current clock provider get disabled, if unused. Also, during the > default clk_disable_unused, if the driver that registered the clock has > the generic clk_sync_state_disable_unused callback set for sync_state, > leave its clocks enabled. > Overall I like this, just a minor thing about ignoring CLK_IGNORE_UNUSED from the sync_stat path below. We've talked about this not being the whole solution, because there might be devices that will enable/disable clocks that will be used by later devices. It seems to me that this would be an additional issue that needs to be fixed - so I don't have a problem with us picking this up as a first step. But for boards where this would be a problem there's no longer a way to opt-out of the disabling of unused clocks. So perhaps we'd want clk_ignore_unused to affect the sync_state based case as well? > Signed-off-by: Abel Vesa <abel.vesa@linaro.org> > --- > drivers/clk/clk.c | 67 +++++++++++++++++++++++++++--------- > include/linux/clk-provider.h | 1 + > 2 files changed, 52 insertions(+), 16 deletions(-) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index 7fc191c15507..ea55806505c0 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -1218,19 +1218,31 @@ static void clk_core_disable_unprepare(struct clk_core *core) > clk_core_unprepare_lock(core); > } > > -static void __init clk_unprepare_unused_subtree(struct clk_core *core) > +static void clk_unprepare_unused_subtree(struct clk_core *core, > + struct device *dev) > { > struct clk_core *child; > > lockdep_assert_held(&prepare_lock); > > hlist_for_each_entry(child, &core->children, child_node) > - clk_unprepare_unused_subtree(child); > + clk_unprepare_unused_subtree(child, dev); > + > + if (dev && core->dev != dev) > + return; > + > + /* > + * clock will be unprepared on sync_state, > + * so leave as is on clk_disable_unused > + */ > + if (!dev && dev_has_sync_state(core->dev) && How about introducing a local variable bool from_sync_state = !!dev, to make these conditionals easier to read? > + core->dev->driver->sync_state == clk_sync_state_disable_unused) > + return; > > if (core->prepare_count) > return; > > - if (core->flags & CLK_IGNORE_UNUSED) > + if (!dev && core->flags & CLK_IGNORE_UNUSED) Iiuc, when being called from the sync_state path, CLK_IGNORE_UNUSED will now be ignored (and the clock will be disabled). We don't have a lot of users of this flag, but would it not make sense to adhere to this flag even in that case? As a continued means to describe a clock which shouldn't be automatically disabled... > return; > > if (clk_pm_runtime_get(core)) > @@ -1248,7 +1260,8 @@ static void __init clk_unprepare_unused_subtree(struct clk_core *core) > clk_pm_runtime_put(core); > } > > -static void __init clk_disable_unused_subtree(struct clk_core *core) > +static void clk_disable_unused_subtree(struct clk_core *core, > + struct device *dev) > { > struct clk_core *child; > unsigned long flags; > @@ -1256,7 +1269,18 @@ static void __init clk_disable_unused_subtree(struct clk_core *core) > lockdep_assert_held(&prepare_lock); > > hlist_for_each_entry(child, &core->children, child_node) > - clk_disable_unused_subtree(child); > + clk_disable_unused_subtree(child, dev); > + > + if (dev && core->dev != dev) > + return; > + > + /* > + * clock will be disabled on sync_state, > + * so leave as is on clk_disable_unused > + */ > + if (!dev && dev_has_sync_state(core->dev) && > + core->dev->driver->sync_state == clk_sync_state_disable_unused) > + return; > > if (core->flags & CLK_OPS_PARENT_ENABLE) > clk_core_prepare_enable(core->parent); > @@ -1269,7 +1293,7 @@ static void __init clk_disable_unused_subtree(struct clk_core *core) > if (core->enable_count) > goto unlock_out; > > - if (core->flags & CLK_IGNORE_UNUSED) > + if (!dev && core->flags & CLK_IGNORE_UNUSED) > goto unlock_out; > > /* > @@ -1302,35 +1326,46 @@ static int __init clk_ignore_unused_setup(char *__unused) > } > __setup("clk_ignore_unused", clk_ignore_unused_setup); > > -static int __init clk_disable_unused(void) > +static void __clk_disable_unused(struct device *dev) > { > struct clk_core *core; > > - if (clk_ignore_unused) { > - pr_warn("clk: Not disabling unused clocks\n"); > - return 0; > - } As mentioned above, I think it's reasonable to keep this here. Regards, Bjorn > - > clk_prepare_lock(); > > hlist_for_each_entry(core, &clk_root_list, child_node) > - clk_disable_unused_subtree(core); > + clk_disable_unused_subtree(core, dev); > > hlist_for_each_entry(core, &clk_orphan_list, child_node) > - clk_disable_unused_subtree(core); > + clk_disable_unused_subtree(core, dev); > > hlist_for_each_entry(core, &clk_root_list, child_node) > - clk_unprepare_unused_subtree(core); > + clk_unprepare_unused_subtree(core, dev); > > hlist_for_each_entry(core, &clk_orphan_list, child_node) > - clk_unprepare_unused_subtree(core); > + clk_unprepare_unused_subtree(core, dev); > > clk_prepare_unlock(); > +} > + > +static int __init clk_disable_unused(void) > +{ > + if (clk_ignore_unused) { > + pr_warn("clk: Not disabling unused clocks\n"); > + return 0; > + } > + > + __clk_disable_unused(NULL); > > return 0; > } > late_initcall_sync(clk_disable_unused); > > +void clk_sync_state_disable_unused(struct device *dev) > +{ > + __clk_disable_unused(dev); > +} > +EXPORT_SYMBOL_GPL(clk_sync_state_disable_unused); > + > static int clk_core_determine_round_nolock(struct clk_core *core, > struct clk_rate_request *req) > { > diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h > index 72d937c03a3e..5d3ed2b14f2c 100644 > --- a/include/linux/clk-provider.h > +++ b/include/linux/clk-provider.h > @@ -679,6 +679,7 @@ struct clk *clk_register_divider_table(struct device *dev, const char *name, > void __iomem *reg, u8 shift, u8 width, > u8 clk_divider_flags, const struct clk_div_table *table, > spinlock_t *lock); > +void clk_sync_state_disable_unused(struct device *dev); > /** > * clk_register_divider - register a divider clock with the clock framework > * @dev: device registering this clock > -- > 2.34.3 >
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 7fc191c15507..ea55806505c0 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1218,19 +1218,31 @@ static void clk_core_disable_unprepare(struct clk_core *core) clk_core_unprepare_lock(core); } -static void __init clk_unprepare_unused_subtree(struct clk_core *core) +static void clk_unprepare_unused_subtree(struct clk_core *core, + struct device *dev) { struct clk_core *child; lockdep_assert_held(&prepare_lock); hlist_for_each_entry(child, &core->children, child_node) - clk_unprepare_unused_subtree(child); + clk_unprepare_unused_subtree(child, dev); + + if (dev && core->dev != dev) + return; + + /* + * clock will be unprepared on sync_state, + * so leave as is on clk_disable_unused + */ + if (!dev && dev_has_sync_state(core->dev) && + core->dev->driver->sync_state == clk_sync_state_disable_unused) + return; if (core->prepare_count) return; - if (core->flags & CLK_IGNORE_UNUSED) + if (!dev && core->flags & CLK_IGNORE_UNUSED) return; if (clk_pm_runtime_get(core)) @@ -1248,7 +1260,8 @@ static void __init clk_unprepare_unused_subtree(struct clk_core *core) clk_pm_runtime_put(core); } -static void __init clk_disable_unused_subtree(struct clk_core *core) +static void clk_disable_unused_subtree(struct clk_core *core, + struct device *dev) { struct clk_core *child; unsigned long flags; @@ -1256,7 +1269,18 @@ static void __init clk_disable_unused_subtree(struct clk_core *core) lockdep_assert_held(&prepare_lock); hlist_for_each_entry(child, &core->children, child_node) - clk_disable_unused_subtree(child); + clk_disable_unused_subtree(child, dev); + + if (dev && core->dev != dev) + return; + + /* + * clock will be disabled on sync_state, + * so leave as is on clk_disable_unused + */ + if (!dev && dev_has_sync_state(core->dev) && + core->dev->driver->sync_state == clk_sync_state_disable_unused) + return; if (core->flags & CLK_OPS_PARENT_ENABLE) clk_core_prepare_enable(core->parent); @@ -1269,7 +1293,7 @@ static void __init clk_disable_unused_subtree(struct clk_core *core) if (core->enable_count) goto unlock_out; - if (core->flags & CLK_IGNORE_UNUSED) + if (!dev && core->flags & CLK_IGNORE_UNUSED) goto unlock_out; /* @@ -1302,35 +1326,46 @@ static int __init clk_ignore_unused_setup(char *__unused) } __setup("clk_ignore_unused", clk_ignore_unused_setup); -static int __init clk_disable_unused(void) +static void __clk_disable_unused(struct device *dev) { struct clk_core *core; - if (clk_ignore_unused) { - pr_warn("clk: Not disabling unused clocks\n"); - return 0; - } - clk_prepare_lock(); hlist_for_each_entry(core, &clk_root_list, child_node) - clk_disable_unused_subtree(core); + clk_disable_unused_subtree(core, dev); hlist_for_each_entry(core, &clk_orphan_list, child_node) - clk_disable_unused_subtree(core); + clk_disable_unused_subtree(core, dev); hlist_for_each_entry(core, &clk_root_list, child_node) - clk_unprepare_unused_subtree(core); + clk_unprepare_unused_subtree(core, dev); hlist_for_each_entry(core, &clk_orphan_list, child_node) - clk_unprepare_unused_subtree(core); + clk_unprepare_unused_subtree(core, dev); clk_prepare_unlock(); +} + +static int __init clk_disable_unused(void) +{ + if (clk_ignore_unused) { + pr_warn("clk: Not disabling unused clocks\n"); + return 0; + } + + __clk_disable_unused(NULL); return 0; } late_initcall_sync(clk_disable_unused); +void clk_sync_state_disable_unused(struct device *dev) +{ + __clk_disable_unused(dev); +} +EXPORT_SYMBOL_GPL(clk_sync_state_disable_unused); + static int clk_core_determine_round_nolock(struct clk_core *core, struct clk_rate_request *req) { diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 72d937c03a3e..5d3ed2b14f2c 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -679,6 +679,7 @@ struct clk *clk_register_divider_table(struct device *dev, const char *name, void __iomem *reg, u8 shift, u8 width, u8 clk_divider_flags, const struct clk_div_table *table, spinlock_t *lock); +void clk_sync_state_disable_unused(struct device *dev); /** * clk_register_divider - register a divider clock with the clock framework * @dev: device registering this clock
There are unused clocks that need to stay enabled on clk_disable_unused, but rather should be disabled later on on sync_state. Provide a generic sync_state callback for the clock providers that register such clocks. Then, use the same mechanism as clk_disable_unused from that generic callback, but pass the device to make sure only the clocks belonging to the current clock provider get disabled, if unused. Also, during the default clk_disable_unused, if the driver that registered the clock has the generic clk_sync_state_disable_unused callback set for sync_state, leave its clocks enabled. Signed-off-by: Abel Vesa <abel.vesa@linaro.org> --- drivers/clk/clk.c | 67 +++++++++++++++++++++++++++--------- include/linux/clk-provider.h | 1 + 2 files changed, 52 insertions(+), 16 deletions(-)