* [RFC 2/2] clk: qcom: sdm845: Add clk_sync_state_disable_unused as sync_state
2022-07-06 15:04 [RFC 1/2] clk: Add generic sync_state callback for disabling unused clocks Abel Vesa
@ 2022-07-06 15:04 ` Abel Vesa
2022-09-29 15:11 ` Bjorn Andersson
2022-07-21 8:19 ` [RFC 1/2] clk: Add generic sync_state callback for disabling unused clocks Abel Vesa
2022-09-29 15:10 ` Bjorn Andersson
2 siblings, 1 reply; 5+ messages in thread
From: Abel Vesa @ 2022-07-06 15:04 UTC (permalink / raw)
To: Mike Turquette, Stephen Boyd, Bjorn Andersson, Dmitry Baryshkov,
Konrad Dybcio
Cc: linux-clk, Linux Kernel Mailing List, linux-arm-msm, Abel Vesa
By adding the newly added clk_sync_state_disable_unused as sync_state
callback to all sdm845 clock providers, we make sure that no clock
belonging to these providers gets disabled on clk_disable_unused,
but rather they are disabled on sync_state, when it is safe, since
all the consumers build as modules have their chance of enabling
their own clocks.
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
---
drivers/clk/qcom/camcc-sdm845.c | 1 +
drivers/clk/qcom/dispcc-sdm845.c | 1 +
drivers/clk/qcom/gcc-sdm845.c | 1 +
drivers/clk/qcom/gpucc-sdm845.c | 1 +
4 files changed, 4 insertions(+)
diff --git a/drivers/clk/qcom/camcc-sdm845.c b/drivers/clk/qcom/camcc-sdm845.c
index 27d44188a7ab..e5aeb832e47b 100644
--- a/drivers/clk/qcom/camcc-sdm845.c
+++ b/drivers/clk/qcom/camcc-sdm845.c
@@ -1743,6 +1743,7 @@ static struct platform_driver cam_cc_sdm845_driver = {
.driver = {
.name = "sdm845-camcc",
.of_match_table = cam_cc_sdm845_match_table,
+ .sync_state = clk_sync_state_disable_unused,
},
};
diff --git a/drivers/clk/qcom/dispcc-sdm845.c b/drivers/clk/qcom/dispcc-sdm845.c
index 735adfefc379..1810d58bad09 100644
--- a/drivers/clk/qcom/dispcc-sdm845.c
+++ b/drivers/clk/qcom/dispcc-sdm845.c
@@ -869,6 +869,7 @@ static struct platform_driver disp_cc_sdm845_driver = {
.driver = {
.name = "disp_cc-sdm845",
.of_match_table = disp_cc_sdm845_match_table,
+ .sync_state = clk_sync_state_disable_unused,
},
};
diff --git a/drivers/clk/qcom/gcc-sdm845.c b/drivers/clk/qcom/gcc-sdm845.c
index 58aa3ec9a7fc..5db75d5ba584 100644
--- a/drivers/clk/qcom/gcc-sdm845.c
+++ b/drivers/clk/qcom/gcc-sdm845.c
@@ -3624,6 +3624,7 @@ static struct platform_driver gcc_sdm845_driver = {
.driver = {
.name = "gcc-sdm845",
.of_match_table = gcc_sdm845_match_table,
+ .sync_state = clk_sync_state_disable_unused,
},
};
diff --git a/drivers/clk/qcom/gpucc-sdm845.c b/drivers/clk/qcom/gpucc-sdm845.c
index 110b54401bc6..622a54a67d32 100644
--- a/drivers/clk/qcom/gpucc-sdm845.c
+++ b/drivers/clk/qcom/gpucc-sdm845.c
@@ -205,6 +205,7 @@ static struct platform_driver gpu_cc_sdm845_driver = {
.driver = {
.name = "sdm845-gpucc",
.of_match_table = gpu_cc_sdm845_match_table,
+ .sync_state = clk_sync_state_disable_unused,
},
};
--
2.34.3
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [RFC 2/2] clk: qcom: sdm845: Add clk_sync_state_disable_unused as sync_state
2022-07-06 15:04 ` [RFC 2/2] clk: qcom: sdm845: Add clk_sync_state_disable_unused as sync_state Abel Vesa
@ 2022-09-29 15:11 ` Bjorn Andersson
0 siblings, 0 replies; 5+ messages in thread
From: Bjorn Andersson @ 2022-09-29 15:11 UTC (permalink / raw)
To: Abel Vesa
Cc: Mike Turquette, Stephen Boyd, Bjorn Andersson, Dmitry Baryshkov,
Konrad Dybcio, linux-clk, Linux Kernel Mailing List,
linux-arm-msm
On Wed, Jul 06, 2022 at 06:04:11PM +0300, Abel Vesa wrote:
> By adding the newly added clk_sync_state_disable_unused as sync_state
> callback to all sdm845 clock providers, we make sure that no clock
> belonging to these providers gets disabled on clk_disable_unused,
> but rather they are disabled on sync_state, when it is safe, since
> all the consumers build as modules have their chance of enabling
> their own clocks.
>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
> Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
> ---
> drivers/clk/qcom/camcc-sdm845.c | 1 +
> drivers/clk/qcom/dispcc-sdm845.c | 1 +
> drivers/clk/qcom/gcc-sdm845.c | 1 +
> drivers/clk/qcom/gpucc-sdm845.c | 1 +
> 4 files changed, 4 insertions(+)
>
> diff --git a/drivers/clk/qcom/camcc-sdm845.c b/drivers/clk/qcom/camcc-sdm845.c
> index 27d44188a7ab..e5aeb832e47b 100644
> --- a/drivers/clk/qcom/camcc-sdm845.c
> +++ b/drivers/clk/qcom/camcc-sdm845.c
> @@ -1743,6 +1743,7 @@ static struct platform_driver cam_cc_sdm845_driver = {
> .driver = {
> .name = "sdm845-camcc",
> .of_match_table = cam_cc_sdm845_match_table,
> + .sync_state = clk_sync_state_disable_unused,
> },
> };
>
> diff --git a/drivers/clk/qcom/dispcc-sdm845.c b/drivers/clk/qcom/dispcc-sdm845.c
> index 735adfefc379..1810d58bad09 100644
> --- a/drivers/clk/qcom/dispcc-sdm845.c
> +++ b/drivers/clk/qcom/dispcc-sdm845.c
> @@ -869,6 +869,7 @@ static struct platform_driver disp_cc_sdm845_driver = {
> .driver = {
> .name = "disp_cc-sdm845",
> .of_match_table = disp_cc_sdm845_match_table,
> + .sync_state = clk_sync_state_disable_unused,
> },
> };
>
> diff --git a/drivers/clk/qcom/gcc-sdm845.c b/drivers/clk/qcom/gcc-sdm845.c
> index 58aa3ec9a7fc..5db75d5ba584 100644
> --- a/drivers/clk/qcom/gcc-sdm845.c
> +++ b/drivers/clk/qcom/gcc-sdm845.c
> @@ -3624,6 +3624,7 @@ static struct platform_driver gcc_sdm845_driver = {
> .driver = {
> .name = "gcc-sdm845",
> .of_match_table = gcc_sdm845_match_table,
> + .sync_state = clk_sync_state_disable_unused,
> },
> };
>
> diff --git a/drivers/clk/qcom/gpucc-sdm845.c b/drivers/clk/qcom/gpucc-sdm845.c
> index 110b54401bc6..622a54a67d32 100644
> --- a/drivers/clk/qcom/gpucc-sdm845.c
> +++ b/drivers/clk/qcom/gpucc-sdm845.c
> @@ -205,6 +205,7 @@ static struct platform_driver gpu_cc_sdm845_driver = {
> .driver = {
> .name = "sdm845-gpucc",
> .of_match_table = gpu_cc_sdm845_match_table,
> + .sync_state = clk_sync_state_disable_unused,
> },
> };
>
> --
> 2.34.3
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC 1/2] clk: Add generic sync_state callback for disabling unused clocks
2022-07-06 15:04 [RFC 1/2] clk: Add generic sync_state callback for disabling unused clocks Abel Vesa
2022-07-06 15:04 ` [RFC 2/2] clk: qcom: sdm845: Add clk_sync_state_disable_unused as sync_state Abel Vesa
@ 2022-07-21 8:19 ` Abel Vesa
2022-09-29 15:10 ` Bjorn Andersson
2 siblings, 0 replies; 5+ messages in thread
From: Abel Vesa @ 2022-07-21 8:19 UTC (permalink / raw)
To: Mike Turquette, Stephen Boyd, Bjorn Andersson, Dmitry Baryshkov,
Konrad Dybcio
Cc: linux-clk, Linux Kernel Mailing List, linux-arm-msm
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
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [RFC 1/2] clk: Add generic sync_state callback for disabling unused clocks
2022-07-06 15:04 [RFC 1/2] clk: Add generic sync_state callback for disabling unused clocks Abel Vesa
2022-07-06 15:04 ` [RFC 2/2] clk: qcom: sdm845: Add clk_sync_state_disable_unused as sync_state Abel Vesa
2022-07-21 8:19 ` [RFC 1/2] clk: Add generic sync_state callback for disabling unused clocks Abel Vesa
@ 2022-09-29 15:10 ` Bjorn Andersson
2 siblings, 0 replies; 5+ messages in thread
From: Bjorn Andersson @ 2022-09-29 15:10 UTC (permalink / raw)
To: Abel Vesa
Cc: Mike Turquette, Stephen Boyd, Bjorn Andersson, Dmitry Baryshkov,
Konrad Dybcio, linux-clk, Linux Kernel Mailing List,
linux-arm-msm
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
>
^ permalink raw reply [flat|nested] 5+ messages in thread