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[PATCH v5 08/10] interconnect: qcom: msm8996: Specify no bus clock scaling on A0NoC

Konrad Dybcio posted 10 patches 2 years, 11 months ago
There is a newer version of this series
[PATCH v5 08/10] interconnect: qcom: msm8996: Specify no bus clock scaling on A0NoC
Posted by Konrad Dybcio 2 years, 11 months ago 
A0NoC only does bus scaling through RPM votes and does not have any
ICC clocks. Describe this.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
 drivers/interconnect/qcom/msm8996.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/interconnect/qcom/msm8996.c b/drivers/interconnect/qcom/msm8996.c
index 1a5e0ad36cc4..45eb8675fb11 100644
--- a/drivers/interconnect/qcom/msm8996.c
+++ b/drivers/interconnect/qcom/msm8996.c
@@ -1817,6 +1817,7 @@ static const struct qcom_icc_desc msm8996_a0noc = {
 	.type = QCOM_ICC_NOC,
 	.nodes = a0noc_nodes,
 	.num_nodes = ARRAY_SIZE(a0noc_nodes),
+	.num_bus_clocks = -1, /* No bus clock scaling */
 	.intf_clocks = a0noc_intf_clocks,
 	.num_intf_clocks = ARRAY_SIZE(a0noc_intf_clocks),
 	.has_bus_pd = true,

-- 
2.39.1
Re: [PATCH v5 08/10] interconnect: qcom: msm8996: Specify no bus clock scaling on A0NoC
Posted by Konrad Dybcio 2 years, 11 months ago 

On 17.02.2023 11:46, Konrad Dybcio wrote:
> A0NoC only does bus scaling through RPM votes and does not have any
> ICC clocks. Describe this.
> 
> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> ---
This is bad, as devm_clk_get_bulk{"", _optional} doesn't
check if num_clocks makes sense and passes "-1" down the
devres alloc chain..

I'll rework this for the next revision by simply assigning
the common "bus", "bus_a" set everywhere instead of relying
on it being there by default..

Konrad
>  drivers/interconnect/qcom/msm8996.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/interconnect/qcom/msm8996.c b/drivers/interconnect/qcom/msm8996.c
> index 1a5e0ad36cc4..45eb8675fb11 100644
> --- a/drivers/interconnect/qcom/msm8996.c
> +++ b/drivers/interconnect/qcom/msm8996.c
> @@ -1817,6 +1817,7 @@ static const struct qcom_icc_desc msm8996_a0noc = {
>  	.type = QCOM_ICC_NOC,
>  	.nodes = a0noc_nodes,
>  	.num_nodes = ARRAY_SIZE(a0noc_nodes),
> +	.num_bus_clocks = -1, /* No bus clock scaling */
>  	.intf_clocks = a0noc_intf_clocks,
>  	.num_intf_clocks = ARRAY_SIZE(a0noc_intf_clocks),
>  	.has_bus_pd = true,
>
Re: [PATCH v5 08/10] interconnect: qcom: msm8996: Specify no bus clock scaling on A0NoC
Posted by Konrad Dybcio 2 years, 11 months ago 

On 17.02.2023 20:27, Konrad Dybcio wrote:
> 
> 
> On 17.02.2023 11:46, Konrad Dybcio wrote:
>> A0NoC only does bus scaling through RPM votes and does not have any
>> ICC clocks. Describe this.
>>
>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
>> ---
> This is bad, as devm_clk_get_bulk{"", _optional} doesn't
> check if num_clocks makes sense and passes "-1" down the
> devres alloc chain..
> 
> I'll rework this for the next revision by simply assigning
> the common "bus", "bus_a" set everywhere instead of relying
> on it being there by default..
Or maybe I shouldn't, as that will require redefining the array
over and over again.. Perhaps just passing <&xo_board>, <&xo_board>
to a0noc's "bus", "bus_a", similar to what's been done on SDM630's
GNoC would be less messy?

Konrad
> 
> Konrad
>>  drivers/interconnect/qcom/msm8996.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/interconnect/qcom/msm8996.c b/drivers/interconnect/qcom/msm8996.c
>> index 1a5e0ad36cc4..45eb8675fb11 100644
>> --- a/drivers/interconnect/qcom/msm8996.c
>> +++ b/drivers/interconnect/qcom/msm8996.c
>> @@ -1817,6 +1817,7 @@ static const struct qcom_icc_desc msm8996_a0noc = {
>>  	.type = QCOM_ICC_NOC,
>>  	.nodes = a0noc_nodes,
>>  	.num_nodes = ARRAY_SIZE(a0noc_nodes),
>> +	.num_bus_clocks = -1, /* No bus clock scaling */
>>  	.intf_clocks = a0noc_intf_clocks,
>>  	.num_intf_clocks = ARRAY_SIZE(a0noc_intf_clocks),
>>  	.has_bus_pd = true,
>>
Re: [PATCH v5 08/10] interconnect: qcom: msm8996: Specify no bus clock scaling on A0NoC
Posted by Dmitry Baryshkov 2 years, 11 months ago 
On Fri, 17 Feb 2023 at 21:53, Konrad Dybcio <konrad.dybcio@linaro.org> wrote:
>
>
>
> On 17.02.2023 20:27, Konrad Dybcio wrote:
> >
> >
> > On 17.02.2023 11:46, Konrad Dybcio wrote:
> >> A0NoC only does bus scaling through RPM votes and does not have any
> >> ICC clocks. Describe this.
> >>
> >> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> >> ---
> > This is bad, as devm_clk_get_bulk{"", _optional} doesn't
> > check if num_clocks makes sense and passes "-1" down the
> > devres alloc chain..
> >
> > I'll rework this for the next revision by simply assigning
> > the common "bus", "bus_a" set everywhere instead of relying
> > on it being there by default..
> Or maybe I shouldn't, as that will require redefining the array
> over and over again.. Perhaps just passing <&xo_board>, <&xo_board>
> to a0noc's "bus", "bus_a", similar to what's been done on SDM630's
> GNoC would be less messy?

What about simply skipping a call to devm_clk_get if num_bus_clocks is negative?

>
> Konrad
> >
> > Konrad
> >>  drivers/interconnect/qcom/msm8996.c | 1 +
> >>  1 file changed, 1 insertion(+)
> >>
> >> diff --git a/drivers/interconnect/qcom/msm8996.c b/drivers/interconnect/qcom/msm8996.c
> >> index 1a5e0ad36cc4..45eb8675fb11 100644
> >> --- a/drivers/interconnect/qcom/msm8996.c
> >> +++ b/drivers/interconnect/qcom/msm8996.c
> >> @@ -1817,6 +1817,7 @@ static const struct qcom_icc_desc msm8996_a0noc = {
> >>      .type = QCOM_ICC_NOC,
> >>      .nodes = a0noc_nodes,
> >>      .num_nodes = ARRAY_SIZE(a0noc_nodes),
> >> +    .num_bus_clocks = -1, /* No bus clock scaling */
> >>      .intf_clocks = a0noc_intf_clocks,
> >>      .num_intf_clocks = ARRAY_SIZE(a0noc_intf_clocks),
> >>      .has_bus_pd = true,
> >>



-- 
With best wishes
Dmitry
Re: [PATCH v5 08/10] interconnect: qcom: msm8996: Specify no bus clock scaling on A0NoC
Posted by Konrad Dybcio 2 years, 11 months ago 

On 17.02.2023 21:26, Dmitry Baryshkov wrote:
> On Fri, 17 Feb 2023 at 21:53, Konrad Dybcio <konrad.dybcio@linaro.org> wrote:
>>
>>
>>
>> On 17.02.2023 20:27, Konrad Dybcio wrote:
>>>
>>>
>>> On 17.02.2023 11:46, Konrad Dybcio wrote:
>>>> A0NoC only does bus scaling through RPM votes and does not have any
>>>> ICC clocks. Describe this.
>>>>
>>>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
>>>> ---
>>> This is bad, as devm_clk_get_bulk{"", _optional} doesn't
>>> check if num_clocks makes sense and passes "-1" down the
>>> devres alloc chain..
>>>
>>> I'll rework this for the next revision by simply assigning
>>> the common "bus", "bus_a" set everywhere instead of relying
>>> on it being there by default..
>> Or maybe I shouldn't, as that will require redefining the array
>> over and over again.. Perhaps just passing <&xo_board>, <&xo_board>
>> to a0noc's "bus", "bus_a", similar to what's been done on SDM630's
>> GNoC would be less messy?
> 
> What about simply skipping a call to devm_clk_get if num_bus_clocks is negative?
I tested that locally before reporting the mistake on my side and
while it works, I just consider it.. ugly, because:

num_clocks =
>0 => use the externally specified num_/clocks (logical)
=0 => use the default 2
<0 => consider there's zero

..but maybe that's just me.. if you don't find it ugly, I may just
go with that.

Konrad
> 
>>
>> Konrad
>>>
>>> Konrad
>>>>  drivers/interconnect/qcom/msm8996.c | 1 +
>>>>  1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/drivers/interconnect/qcom/msm8996.c b/drivers/interconnect/qcom/msm8996.c
>>>> index 1a5e0ad36cc4..45eb8675fb11 100644
>>>> --- a/drivers/interconnect/qcom/msm8996.c
>>>> +++ b/drivers/interconnect/qcom/msm8996.c
>>>> @@ -1817,6 +1817,7 @@ static const struct qcom_icc_desc msm8996_a0noc = {
>>>>      .type = QCOM_ICC_NOC,
>>>>      .nodes = a0noc_nodes,
>>>>      .num_nodes = ARRAY_SIZE(a0noc_nodes),
>>>> +    .num_bus_clocks = -1, /* No bus clock scaling */
>>>>      .intf_clocks = a0noc_intf_clocks,
>>>>      .num_intf_clocks = ARRAY_SIZE(a0noc_intf_clocks),
>>>>      .has_bus_pd = true,
>>>>
> 
> 
>
Re: [PATCH v5 08/10] interconnect: qcom: msm8996: Specify no bus clock scaling on A0NoC
Posted by Bjorn Andersson 2 years, 11 months ago 
On Fri, Feb 17, 2023 at 09:28:54PM +0100, Konrad Dybcio wrote:
> 
> 
> On 17.02.2023 21:26, Dmitry Baryshkov wrote:
> > On Fri, 17 Feb 2023 at 21:53, Konrad Dybcio <konrad.dybcio@linaro.org> wrote:
> >>
> >>
> >>
> >> On 17.02.2023 20:27, Konrad Dybcio wrote:
> >>>
> >>>
> >>> On 17.02.2023 11:46, Konrad Dybcio wrote:
> >>>> A0NoC only does bus scaling through RPM votes and does not have any
> >>>> ICC clocks. Describe this.
> >>>>
> >>>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> >>>> ---
> >>> This is bad, as devm_clk_get_bulk{"", _optional} doesn't
> >>> check if num_clocks makes sense and passes "-1" down the
> >>> devres alloc chain..
> >>>
> >>> I'll rework this for the next revision by simply assigning
> >>> the common "bus", "bus_a" set everywhere instead of relying
> >>> on it being there by default..
> >> Or maybe I shouldn't, as that will require redefining the array
> >> over and over again.. Perhaps just passing <&xo_board>, <&xo_board>
> >> to a0noc's "bus", "bus_a", similar to what's been done on SDM630's
> >> GNoC would be less messy?
> > 
> > What about simply skipping a call to devm_clk_get if num_bus_clocks is negative?
> I tested that locally before reporting the mistake on my side and
> while it works, I just consider it.. ugly, because:
> 
> num_clocks =
> >0 => use the externally specified num_/clocks (logical)
> =0 => use the default 2

Why not let go of this "convenience" and have num_clocks actually mean
number of clocks?

Regards,
Bjorn

> <0 => consider there's zero
> 
> ..but maybe that's just me.. if you don't find it ugly, I may just
> go with that.
> 
> Konrad
> > 
> >>
> >> Konrad
> >>>
> >>> Konrad
> >>>>  drivers/interconnect/qcom/msm8996.c | 1 +
> >>>>  1 file changed, 1 insertion(+)
> >>>>
> >>>> diff --git a/drivers/interconnect/qcom/msm8996.c b/drivers/interconnect/qcom/msm8996.c
> >>>> index 1a5e0ad36cc4..45eb8675fb11 100644
> >>>> --- a/drivers/interconnect/qcom/msm8996.c
> >>>> +++ b/drivers/interconnect/qcom/msm8996.c
> >>>> @@ -1817,6 +1817,7 @@ static const struct qcom_icc_desc msm8996_a0noc = {
> >>>>      .type = QCOM_ICC_NOC,
> >>>>      .nodes = a0noc_nodes,
> >>>>      .num_nodes = ARRAY_SIZE(a0noc_nodes),
> >>>> +    .num_bus_clocks = -1, /* No bus clock scaling */
> >>>>      .intf_clocks = a0noc_intf_clocks,
> >>>>      .num_intf_clocks = ARRAY_SIZE(a0noc_intf_clocks),
> >>>>      .has_bus_pd = true,
> >>>>
> > 
> > 
> >
Re: [PATCH v5 08/10] interconnect: qcom: msm8996: Specify no bus clock scaling on A0NoC
Posted by Konrad Dybcio 2 years, 11 months ago 

On 23.02.2023 15:07, Bjorn Andersson wrote:
> On Fri, Feb 17, 2023 at 09:28:54PM +0100, Konrad Dybcio wrote:
>>
>>
>> On 17.02.2023 21:26, Dmitry Baryshkov wrote:
>>> On Fri, 17 Feb 2023 at 21:53, Konrad Dybcio <konrad.dybcio@linaro.org> wrote:
>>>>
>>>>
>>>>
>>>> On 17.02.2023 20:27, Konrad Dybcio wrote:
>>>>>
>>>>>
>>>>> On 17.02.2023 11:46, Konrad Dybcio wrote:
>>>>>> A0NoC only does bus scaling through RPM votes and does not have any
>>>>>> ICC clocks. Describe this.
>>>>>>
>>>>>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
>>>>>> ---
>>>>> This is bad, as devm_clk_get_bulk{"", _optional} doesn't
>>>>> check if num_clocks makes sense and passes "-1" down the
>>>>> devres alloc chain..
>>>>>
>>>>> I'll rework this for the next revision by simply assigning
>>>>> the common "bus", "bus_a" set everywhere instead of relying
>>>>> on it being there by default..
>>>> Or maybe I shouldn't, as that will require redefining the array
>>>> over and over again.. Perhaps just passing <&xo_board>, <&xo_board>
>>>> to a0noc's "bus", "bus_a", similar to what's been done on SDM630's
>>>> GNoC would be less messy?
>>>
>>> What about simply skipping a call to devm_clk_get if num_bus_clocks is negative?
>> I tested that locally before reporting the mistake on my side and
>> while it works, I just consider it.. ugly, because:
>>
>> num_clocks =
>>> 0 => use the externally specified num_/clocks (logical)
>> =0 => use the default 2
> 
> Why not let go of this "convenience" and have num_clocks actually mean
> number of clocks?
Sounds good.. Should I keep the default "bus", "bus_a" on absence of
.bus_clocks still, to avoid duplicating objects?

Konrad

> 
> Regards,
> Bjorn
> 
>> <0 => consider there's zero
>>
>> ..but maybe that's just me.. if you don't find it ugly, I may just
>> go with that.
>>
>> Konrad
>>>
>>>>
>>>> Konrad
>>>>>
>>>>> Konrad
>>>>>>  drivers/interconnect/qcom/msm8996.c | 1 +
>>>>>>  1 file changed, 1 insertion(+)
>>>>>>
>>>>>> diff --git a/drivers/interconnect/qcom/msm8996.c b/drivers/interconnect/qcom/msm8996.c
>>>>>> index 1a5e0ad36cc4..45eb8675fb11 100644
>>>>>> --- a/drivers/interconnect/qcom/msm8996.c
>>>>>> +++ b/drivers/interconnect/qcom/msm8996.c
>>>>>> @@ -1817,6 +1817,7 @@ static const struct qcom_icc_desc msm8996_a0noc = {
>>>>>>      .type = QCOM_ICC_NOC,
>>>>>>      .nodes = a0noc_nodes,
>>>>>>      .num_nodes = ARRAY_SIZE(a0noc_nodes),
>>>>>> +    .num_bus_clocks = -1, /* No bus clock scaling */
>>>>>>      .intf_clocks = a0noc_intf_clocks,
>>>>>>      .num_intf_clocks = ARRAY_SIZE(a0noc_intf_clocks),
>>>>>>      .has_bus_pd = true,
>>>>>>
>>>
>>>
>>>
Re: [PATCH v5 08/10] interconnect: qcom: msm8996: Specify no bus clock scaling on A0NoC
Posted by Dmitry Baryshkov 2 years, 11 months ago 
On 17/02/2023 22:28, Konrad Dybcio wrote:
> 
> 
> On 17.02.2023 21:26, Dmitry Baryshkov wrote:
>> On Fri, 17 Feb 2023 at 21:53, Konrad Dybcio <konrad.dybcio@linaro.org> wrote:
>>>
>>>
>>>
>>> On 17.02.2023 20:27, Konrad Dybcio wrote:
>>>>
>>>>
>>>> On 17.02.2023 11:46, Konrad Dybcio wrote:
>>>>> A0NoC only does bus scaling through RPM votes and does not have any
>>>>> ICC clocks. Describe this.
>>>>>
>>>>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
>>>>> ---
>>>> This is bad, as devm_clk_get_bulk{"", _optional} doesn't
>>>> check if num_clocks makes sense and passes "-1" down the
>>>> devres alloc chain..
>>>>
>>>> I'll rework this for the next revision by simply assigning
>>>> the common "bus", "bus_a" set everywhere instead of relying
>>>> on it being there by default..
>>> Or maybe I shouldn't, as that will require redefining the array
>>> over and over again.. Perhaps just passing <&xo_board>, <&xo_board>
>>> to a0noc's "bus", "bus_a", similar to what's been done on SDM630's
>>> GNoC would be less messy?
>>
>> What about simply skipping a call to devm_clk_get if num_bus_clocks is negative?
> I tested that locally before reporting the mistake on my side and
> while it works, I just consider it.. ugly, because:
> 
> num_clocks =
>> 0 => use the externally specified num_/clocks (logical)
> =0 => use the default 2
> <0 => consider there's zero
> 
> ..but maybe that's just me.. if you don't find it ugly, I may just
> go with that.

Would 'lesser ugliness' count? Maybe add a define 'ICC_RPM_NO_CLOCKS = 
-1'? I think that spawning default bus & bus_a everywhere would be worse.

When this driver is rewritten in Rust, we'll have a clear distinction 
between None (meaning default two clocks) and Some(0) (meaning no 
clocks). Wait, does that sound even more ugly?

-- 
With best wishes
Dmitry

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