Some of the clocks are managed by remote cores and we're not supposed
to alter their parameters. Monitoring them may still be useful, e.g.
for getting the correct rates of their children. This series attempts
to solve this problem without compromising on either of them.
Signed-off-by: Konrad Dybcio <[email protected]>
---
Konrad Dybcio (2):
clk: qcom: rcg2: Introduce read-only RCG2 ops
clk: qcom: gcc-msm8996: Use read-only RCG ops for RPM bus clocks
drivers/clk/qcom/clk-rcg.h | 1 +
drivers/clk/qcom/clk-rcg2.c | 8 ++++++++
drivers/clk/qcom/gcc-msm8996.c | 6 +++---
3 files changed, 12 insertions(+), 3 deletions(-)
---
base-commit: 53ab6975c12d1ad86c599a8927e8c698b144d669
change-id: 20230612-topic-rcg2_ro-1450a076eda9
Best regards,
--
Konrad Dybcio <[email protected]>
Some clocks are physically part of a clock controller block (e.g. GCC),
but are under no circumstances supposed to be touched from HLOS/APSS, as
another subsystem manages them, and trying to alter its configuration
may (and likely will) wreck total havoc over whatever the clock is
attached to.
Add read-only ops for RCG clocks. This allows us to peak at the rates
(and other configuration parameters) of such clocks without the risk
of messing up half of the SoC due to an erroneous CCF call.
Signed-off-by: Konrad Dybcio <[email protected]>
---
drivers/clk/qcom/clk-rcg.h | 1 +
drivers/clk/qcom/clk-rcg2.c | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/drivers/clk/qcom/clk-rcg.h b/drivers/clk/qcom/clk-rcg.h
index e6d84c8c7989..4b4ff156539f 100644
--- a/drivers/clk/qcom/clk-rcg.h
+++ b/drivers/clk/qcom/clk-rcg.h
@@ -170,6 +170,7 @@ struct clk_rcg2_gfx3d {
extern const struct clk_ops clk_rcg2_ops;
extern const struct clk_ops clk_rcg2_floor_ops;
extern const struct clk_ops clk_rcg2_mux_closest_ops;
+extern const struct clk_ops clk_rcg2_ro_ops;
extern const struct clk_ops clk_edp_pixel_ops;
extern const struct clk_ops clk_byte_ops;
extern const struct clk_ops clk_byte2_ops;
diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
index e22baf3a7112..71de1cd8d45b 100644
--- a/drivers/clk/qcom/clk-rcg2.c
+++ b/drivers/clk/qcom/clk-rcg2.c
@@ -518,6 +518,14 @@ const struct clk_ops clk_rcg2_mux_closest_ops = {
};
EXPORT_SYMBOL_GPL(clk_rcg2_mux_closest_ops);
+const struct clk_ops clk_rcg2_ro_ops = {
+ .is_enabled = clk_rcg2_is_enabled,
+ .get_parent = clk_rcg2_get_parent,
+ .recalc_rate = clk_rcg2_recalc_rate,
+ .get_duty_cycle = clk_rcg2_get_duty_cycle,
+};
+EXPORT_SYMBOL_GPL(clk_rcg2_ro_ops);
+
struct frac_entry {
int num;
int den;
--
2.41.0
The config/periph/system NoC clocks are wholly controlled by the
RPM firmware and Linux should never ever alter their configuration.
Switch them over to read-only ops to avoid that.
Fixes: b1e010c0730a ("clk: qcom: Add MSM8996 Global Clock Control (GCC) driver")
Signed-off-by: Konrad Dybcio <[email protected]>
---
drivers/clk/qcom/gcc-msm8996.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/clk/qcom/gcc-msm8996.c b/drivers/clk/qcom/gcc-msm8996.c
index 5e44d1bcca9e..588e3b67657a 100644
--- a/drivers/clk/qcom/gcc-msm8996.c
+++ b/drivers/clk/qcom/gcc-msm8996.c
@@ -264,7 +264,7 @@ static struct clk_rcg2 system_noc_clk_src = {
.name = "system_noc_clk_src",
.parent_data = gcc_xo_gpll0_gpll0_early_div,
.num_parents = ARRAY_SIZE(gcc_xo_gpll0_gpll0_early_div),
- .ops = &clk_rcg2_ops,
+ .ops = &clk_rcg2_ro_ops,
},
};
@@ -284,7 +284,7 @@ static struct clk_rcg2 config_noc_clk_src = {
.name = "config_noc_clk_src",
.parent_data = gcc_xo_gpll0,
.num_parents = ARRAY_SIZE(gcc_xo_gpll0),
- .ops = &clk_rcg2_ops,
+ .ops = &clk_rcg2_ro_ops,
},
};
@@ -306,7 +306,7 @@ static struct clk_rcg2 periph_noc_clk_src = {
.name = "periph_noc_clk_src",
.parent_data = gcc_xo_gpll0,
.num_parents = ARRAY_SIZE(gcc_xo_gpll0),
- .ops = &clk_rcg2_ops,
+ .ops = &clk_rcg2_ro_ops,
},
};
--
2.41.0
On Mon, Jun 12, 2023 at 11:22:48AM +0200, Konrad Dybcio wrote:
> The config/periph/system NoC clocks are wholly controlled by the
> RPM firmware and Linux should never ever alter their configuration.
>
> Switch them over to read-only ops to avoid that.
>
> Fixes: b1e010c0730a ("clk: qcom: Add MSM8996 Global Clock Control (GCC) driver")
> Signed-off-by: Konrad Dybcio <[email protected]>
> ---
> drivers/clk/qcom/gcc-msm8996.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clk/qcom/gcc-msm8996.c b/drivers/clk/qcom/gcc-msm8996.c
> index 5e44d1bcca9e..588e3b67657a 100644
> --- a/drivers/clk/qcom/gcc-msm8996.c
> +++ b/drivers/clk/qcom/gcc-msm8996.c
> @@ -264,7 +264,7 @@ static struct clk_rcg2 system_noc_clk_src = {
> .name = "system_noc_clk_src",
> .parent_data = gcc_xo_gpll0_gpll0_early_div,
> .num_parents = ARRAY_SIZE(gcc_xo_gpll0_gpll0_early_div),
> - .ops = &clk_rcg2_ops,
> + .ops = &clk_rcg2_ro_ops,
> },
> };
>
> @@ -284,7 +284,7 @@ static struct clk_rcg2 config_noc_clk_src = {
> .name = "config_noc_clk_src",
> .parent_data = gcc_xo_gpll0,
> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
> - .ops = &clk_rcg2_ops,
> + .ops = &clk_rcg2_ro_ops,
> },
> };
>
> @@ -306,7 +306,7 @@ static struct clk_rcg2 periph_noc_clk_src = {
> .name = "periph_noc_clk_src",
> .parent_data = gcc_xo_gpll0,
> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
> - .ops = &clk_rcg2_ops,
> + .ops = &clk_rcg2_ro_ops,
> },
> };
>
If the rcg is read-only then it shouldn't need a .freq_tbl (the
.recalc_rate() works without it). These clocks have one for some reason.
Maybe we should also set .flags = CLK_GET_RATE_NOCACHE to ensure that
clk_get_rate() doesn't return some stale value? Although I'm not sure if
it's enough to set it here or if it would need to be set on all child
clocks as well.
Thanks,
Stephan
On 12.06.2023 12:17, Stephan Gerhold wrote:
> On Mon, Jun 12, 2023 at 11:22:48AM +0200, Konrad Dybcio wrote:
>> The config/periph/system NoC clocks are wholly controlled by the
>> RPM firmware and Linux should never ever alter their configuration.
>>
>> Switch them over to read-only ops to avoid that.
>>
>> Fixes: b1e010c0730a ("clk: qcom: Add MSM8996 Global Clock Control (GCC) driver")
>> Signed-off-by: Konrad Dybcio <[email protected]>
>> ---
>> drivers/clk/qcom/gcc-msm8996.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/clk/qcom/gcc-msm8996.c b/drivers/clk/qcom/gcc-msm8996.c
>> index 5e44d1bcca9e..588e3b67657a 100644
>> --- a/drivers/clk/qcom/gcc-msm8996.c
>> +++ b/drivers/clk/qcom/gcc-msm8996.c
>> @@ -264,7 +264,7 @@ static struct clk_rcg2 system_noc_clk_src = {
>> .name = "system_noc_clk_src",
>> .parent_data = gcc_xo_gpll0_gpll0_early_div,
>> .num_parents = ARRAY_SIZE(gcc_xo_gpll0_gpll0_early_div),
>> - .ops = &clk_rcg2_ops,
>> + .ops = &clk_rcg2_ro_ops,
>> },
>> };
>>
>> @@ -284,7 +284,7 @@ static struct clk_rcg2 config_noc_clk_src = {
>> .name = "config_noc_clk_src",
>> .parent_data = gcc_xo_gpll0,
>> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
>> - .ops = &clk_rcg2_ops,
>> + .ops = &clk_rcg2_ro_ops,
>> },
>> };
>>
>> @@ -306,7 +306,7 @@ static struct clk_rcg2 periph_noc_clk_src = {
>> .name = "periph_noc_clk_src",
>> .parent_data = gcc_xo_gpll0,
>> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
>> - .ops = &clk_rcg2_ops,
>> + .ops = &clk_rcg2_ro_ops,
>> },
>> };
>>
>
> If the rcg is read-only then it shouldn't need a .freq_tbl (the
> .recalc_rate() works without it). These clocks have one for some reason.
.get_parent needs it
>
> Maybe we should also set .flags = CLK_GET_RATE_NOCACHE to ensure that
> clk_get_rate() doesn't return some stale value? Although I'm not sure if
> it's enough to set it here or if it would need to be set on all child
> clocks as well.
Hm, I'm not sure if it makes sense for the children..
Konrad
>
> Thanks,
> Stephan
On Mon, Jun 12, 2023 at 01:46:26PM +0200, Konrad Dybcio wrote:
> On 12.06.2023 12:17, Stephan Gerhold wrote:
> > On Mon, Jun 12, 2023 at 11:22:48AM +0200, Konrad Dybcio wrote:
> >> The config/periph/system NoC clocks are wholly controlled by the
> >> RPM firmware and Linux should never ever alter their configuration.
> >>
> >> Switch them over to read-only ops to avoid that.
> >>
> >> Fixes: b1e010c0730a ("clk: qcom: Add MSM8996 Global Clock Control (GCC) driver")
> >> Signed-off-by: Konrad Dybcio <[email protected]>
> >> ---
> >> drivers/clk/qcom/gcc-msm8996.c | 6 +++---
> >> 1 file changed, 3 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/drivers/clk/qcom/gcc-msm8996.c b/drivers/clk/qcom/gcc-msm8996.c
> >> index 5e44d1bcca9e..588e3b67657a 100644
> >> --- a/drivers/clk/qcom/gcc-msm8996.c
> >> +++ b/drivers/clk/qcom/gcc-msm8996.c
> >> @@ -264,7 +264,7 @@ static struct clk_rcg2 system_noc_clk_src = {
> >> .name = "system_noc_clk_src",
> >> .parent_data = gcc_xo_gpll0_gpll0_early_div,
> >> .num_parents = ARRAY_SIZE(gcc_xo_gpll0_gpll0_early_div),
> >> - .ops = &clk_rcg2_ops,
> >> + .ops = &clk_rcg2_ro_ops,
> >> },
> >> };
> >>
> >> @@ -284,7 +284,7 @@ static struct clk_rcg2 config_noc_clk_src = {
> >> .name = "config_noc_clk_src",
> >> .parent_data = gcc_xo_gpll0,
> >> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
> >> - .ops = &clk_rcg2_ops,
> >> + .ops = &clk_rcg2_ro_ops,
> >> },
> >> };
> >>
> >> @@ -306,7 +306,7 @@ static struct clk_rcg2 periph_noc_clk_src = {
> >> .name = "periph_noc_clk_src",
> >> .parent_data = gcc_xo_gpll0,
> >> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
> >> - .ops = &clk_rcg2_ops,
> >> + .ops = &clk_rcg2_ro_ops,
> >> },
> >> };
> >>
> >
> > If the rcg is read-only then it shouldn't need a .freq_tbl (the
> > .recalc_rate() works without it). These clocks have one for some reason.
> .get_parent needs it
>
Hm? .get_parent uses the ->parent_map but not the ->freq_tbl as far as I
can see. :)
Stephan
On 12.06.2023 14:23, Stephan Gerhold wrote:
> On Mon, Jun 12, 2023 at 01:46:26PM +0200, Konrad Dybcio wrote:
>> On 12.06.2023 12:17, Stephan Gerhold wrote:
>>> On Mon, Jun 12, 2023 at 11:22:48AM +0200, Konrad Dybcio wrote:
>>>> The config/periph/system NoC clocks are wholly controlled by the
>>>> RPM firmware and Linux should never ever alter their configuration.
>>>>
>>>> Switch them over to read-only ops to avoid that.
>>>>
>>>> Fixes: b1e010c0730a ("clk: qcom: Add MSM8996 Global Clock Control (GCC) driver")
>>>> Signed-off-by: Konrad Dybcio <[email protected]>
>>>> ---
>>>> drivers/clk/qcom/gcc-msm8996.c | 6 +++---
>>>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/drivers/clk/qcom/gcc-msm8996.c b/drivers/clk/qcom/gcc-msm8996.c
>>>> index 5e44d1bcca9e..588e3b67657a 100644
>>>> --- a/drivers/clk/qcom/gcc-msm8996.c
>>>> +++ b/drivers/clk/qcom/gcc-msm8996.c
>>>> @@ -264,7 +264,7 @@ static struct clk_rcg2 system_noc_clk_src = {
>>>> .name = "system_noc_clk_src",
>>>> .parent_data = gcc_xo_gpll0_gpll0_early_div,
>>>> .num_parents = ARRAY_SIZE(gcc_xo_gpll0_gpll0_early_div),
>>>> - .ops = &clk_rcg2_ops,
>>>> + .ops = &clk_rcg2_ro_ops,
>>>> },
>>>> };
>>>>
>>>> @@ -284,7 +284,7 @@ static struct clk_rcg2 config_noc_clk_src = {
>>>> .name = "config_noc_clk_src",
>>>> .parent_data = gcc_xo_gpll0,
>>>> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
>>>> - .ops = &clk_rcg2_ops,
>>>> + .ops = &clk_rcg2_ro_ops,
>>>> },
>>>> };
>>>>
>>>> @@ -306,7 +306,7 @@ static struct clk_rcg2 periph_noc_clk_src = {
>>>> .name = "periph_noc_clk_src",
>>>> .parent_data = gcc_xo_gpll0,
>>>> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
>>>> - .ops = &clk_rcg2_ops,
>>>> + .ops = &clk_rcg2_ro_ops,
>>>> },
>>>> };
>>>>
>>>
>>> If the rcg is read-only then it shouldn't need a .freq_tbl (the
>>> .recalc_rate() works without it). These clocks have one for some reason.
>> .get_parent needs it
>>
>
> Hm? .get_parent uses the ->parent_map but not the ->freq_tbl as far as I
> can see. :)
Brainfart. I think the ftbls can be removed.
Konrad
>
> Stephan
On Mon, Jun 12, 2023 at 11:22:48AM +0200, Konrad Dybcio wrote:
> The config/periph/system NoC clocks are wholly controlled by the
> RPM firmware and Linux should never ever alter their configuration.
>
Does Linux need to know about them?
Regards,
Bjorn
> Switch them over to read-only ops to avoid that.
>
> Fixes: b1e010c0730a ("clk: qcom: Add MSM8996 Global Clock Control (GCC) driver")
> Signed-off-by: Konrad Dybcio <[email protected]>
> ---
> drivers/clk/qcom/gcc-msm8996.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clk/qcom/gcc-msm8996.c b/drivers/clk/qcom/gcc-msm8996.c
> index 5e44d1bcca9e..588e3b67657a 100644
> --- a/drivers/clk/qcom/gcc-msm8996.c
> +++ b/drivers/clk/qcom/gcc-msm8996.c
> @@ -264,7 +264,7 @@ static struct clk_rcg2 system_noc_clk_src = {
> .name = "system_noc_clk_src",
> .parent_data = gcc_xo_gpll0_gpll0_early_div,
> .num_parents = ARRAY_SIZE(gcc_xo_gpll0_gpll0_early_div),
> - .ops = &clk_rcg2_ops,
> + .ops = &clk_rcg2_ro_ops,
> },
> };
>
> @@ -284,7 +284,7 @@ static struct clk_rcg2 config_noc_clk_src = {
> .name = "config_noc_clk_src",
> .parent_data = gcc_xo_gpll0,
> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
> - .ops = &clk_rcg2_ops,
> + .ops = &clk_rcg2_ro_ops,
> },
> };
>
> @@ -306,7 +306,7 @@ static struct clk_rcg2 periph_noc_clk_src = {
> .name = "periph_noc_clk_src",
> .parent_data = gcc_xo_gpll0,
> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
> - .ops = &clk_rcg2_ops,
> + .ops = &clk_rcg2_ro_ops,
> },
> };
>
>
> --
> 2.41.0
>
On 13.06.2023 19:56, Bjorn Andersson wrote:
> On Mon, Jun 12, 2023 at 11:22:48AM +0200, Konrad Dybcio wrote:
>> The config/periph/system NoC clocks are wholly controlled by the
>> RPM firmware and Linux should never ever alter their configuration.
>>
>
> Does Linux need to know about them?
Not really, but it allows us to get rates of their children.
We can get rid of them if one can argue debugcc is enough. Unless
we need clk_get_rate for some reason.
Konrad
>
> Regards,
> Bjorn
>
>> Switch them over to read-only ops to avoid that.
>>
>> Fixes: b1e010c0730a ("clk: qcom: Add MSM8996 Global Clock Control (GCC) driver")
>> Signed-off-by: Konrad Dybcio <[email protected]>
>> ---
>> drivers/clk/qcom/gcc-msm8996.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/clk/qcom/gcc-msm8996.c b/drivers/clk/qcom/gcc-msm8996.c
>> index 5e44d1bcca9e..588e3b67657a 100644
>> --- a/drivers/clk/qcom/gcc-msm8996.c
>> +++ b/drivers/clk/qcom/gcc-msm8996.c
>> @@ -264,7 +264,7 @@ static struct clk_rcg2 system_noc_clk_src = {
>> .name = "system_noc_clk_src",
>> .parent_data = gcc_xo_gpll0_gpll0_early_div,
>> .num_parents = ARRAY_SIZE(gcc_xo_gpll0_gpll0_early_div),
>> - .ops = &clk_rcg2_ops,
>> + .ops = &clk_rcg2_ro_ops,
>> },
>> };
>>
>> @@ -284,7 +284,7 @@ static struct clk_rcg2 config_noc_clk_src = {
>> .name = "config_noc_clk_src",
>> .parent_data = gcc_xo_gpll0,
>> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
>> - .ops = &clk_rcg2_ops,
>> + .ops = &clk_rcg2_ro_ops,
>> },
>> };
>>
>> @@ -306,7 +306,7 @@ static struct clk_rcg2 periph_noc_clk_src = {
>> .name = "periph_noc_clk_src",
>> .parent_data = gcc_xo_gpll0,
>> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
>> - .ops = &clk_rcg2_ops,
>> + .ops = &clk_rcg2_ro_ops,
>> },
>> };
>>
>>
>> --
>> 2.41.0
>>
On 13.06.2023 19:54, Konrad Dybcio wrote:
>
>
> On 13.06.2023 19:56, Bjorn Andersson wrote:
>> On Mon, Jun 12, 2023 at 11:22:48AM +0200, Konrad Dybcio wrote:
>>> The config/periph/system NoC clocks are wholly controlled by the
>>> RPM firmware and Linux should never ever alter their configuration.
>>>
>>
>> Does Linux need to know about them?
> Not really, but it allows us to get rates of their children.
>
> We can get rid of them if one can argue debugcc is enough. Unless
> we need clk_get_rate for some reason.
>
Any opinions?
Konrad