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Message-ID: <7b8f359f-de8d-4ace-d28d-8242683e1f8c@quicinc.com>
Date:   Thu, 9 Dec 2021 21:07:06 +0530
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Subject: Re: [PATCH v2 2/3] soc: qcom: rpmhpd: Remove mx/cx relationship on
 sc7280
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From:   Rajendra Nayak <quic_rjendra@quicinc.com>
To:     Bjorn Andersson <bjorn.andersson@linaro.org>
Cc:     agross@kernel.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org, swboyd@chromium.org, mka@chromium.org
References: <1638871712-18636-1-git-send-email-quic_rjendra@quicinc.com>
 <1638871712-18636-3-git-send-email-quic_rjendra@quicinc.com>
 <YbEYyGHqaHGeRXsV@builder.lan>
 <7e9f6cbe-17c9-53ff-95a8-2f2bbdeb1d23@quicinc.com>
In-Reply-To: <7e9f6cbe-17c9-53ff-95a8-2f2bbdeb1d23@quicinc.com>
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On 12/9/2021 12:29 PM, Rajendra Nayak wrote:
> 
> On 12/9/2021 2:12 AM, Bjorn Andersson wrote:
>> On Tue 07 Dec 04:08 CST 2021, Rajendra Nayak wrote:
>>
>>> While the requirement to specify the active + sleep and active-only MX
>>> power-domains as the parents of the corresponding CX power domains is
>>> applicable for most SoCs, we have some like the sc7280 where this
>>> dependency is not applicable.
>>> Define new rpmhpd structs for cx and cx_ao without the mx as
>>> parent and use them for sc7280.
>>>
>>> Signed-off-by: Rajendra Nayak <quic_rjendra@quicinc.com>
>>> ---
>>>   drivers/soc/qcom/rpmhpd.c | 18 ++++++++++++++++--
>>>   1 file changed, 16 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/soc/qcom/rpmhpd.c b/drivers/soc/qcom/rpmhpd.c
>>> index c71481d..4599efe 100644
>>> --- a/drivers/soc/qcom/rpmhpd.c
>>> +++ b/drivers/soc/qcom/rpmhpd.c
>>> @@ -120,6 +120,20 @@ static struct rpmhpd cx_ao = {
>>>       .res_name = "cx.lvl",
>>>   };
>>> +static struct rpmhpd cx_ao_no_parent;
>>> +static struct rpmhpd cx_no_parent = {
>>
>> There are multiple variations of how each of these can be parented, but
>> only one way they can be without a parent. So how about we turn this the
>> other way around?
>>
>> I.e. let's name this one "cx" and the existing one "cx_w_mx_parent".
>>
>>
>> This will be particularly useful when you look at mmcx, which on
>> 8150/8180 has mx as parent and on 8450 has cx as parent.

I noticed mmcx on 8150/8180 does not have mx as parent, nevertheless
I went ahead and moved to the _w_<parent-name>_parent suffix because
it made sense if we did run into a situation like this in the future.

>>
>>
>> PS. Unfortunately I had merged 8450 since you wrote this series, I tried
>> to just fix it up as I applied your patch, but noticed 8450_cx and
>> 8450_mmcx and wanted to get your opinion on this first.
> 
> I agree that sounds like a reasonable thing to do, I hadn't looked at 8450
> so did not notice it, I will rebase my patches on top and repost.
> 
>>
>> Regards,
>> Bjorn
>>
>>> +    .pd = { .name = "cx", },
>>> +    .peer = &cx_ao_no_parent,
>>> +    .res_name = "cx.lvl",
>>> +};
>>> +
>>> +static struct rpmhpd cx_ao_no_parent = {
>>> +    .pd = { .name = "cx_ao", },
>>> +    .active_only = true,
>>> +    .peer = &cx_no_parent,
>>> +    .res_name = "cx.lvl",
>>> +};
>>> +
>>>   static struct rpmhpd mmcx_ao;
>>>   static struct rpmhpd mmcx = {
>>>       .pd = { .name = "mmcx", },
>>> @@ -273,8 +287,8 @@ static const struct rpmhpd_desc sc7180_desc = {
>>>   /* SC7280 RPMH powerdomains */
>>>   static struct rpmhpd *sc7280_rpmhpds[] = {
>>> -    [SC7280_CX] = &cx,
>>> -    [SC7280_CX_AO] = &cx_ao,
>>> +    [SC7280_CX] = &cx_no_parent,
>>> +    [SC7280_CX_AO] = &cx_ao_no_parent,
>>>       [SC7280_EBI] = &ebi,
>>>       [SC7280_GFX] = &gfx,
>>>       [SC7280_MX] = &mx,
>>> -- 
>>> 2.7.4
>>>