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Date:   Mon, 27 Jul 2020 12:20:38 +0530
From:   sbhanu@codeaurora.org
To:     Matthias Kaehlcke <mka@chromium.org>
Cc:     adrian.hunter@intel.com, ulf.hansson@linaro.org,
        robh+dt@kernel.org, linux-mmc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        devicetree@vger.kernel.org, agross@kernel.org,
        bjorn.andersson@linaro.org, rnayak@codeaurora.org,
        Pradeep P V K <ppvk@codeaurora.org>,
        devicetree-owner@vger.kernel.org
Subject: Re: [PATCH V2] arm64: dts: qcom: sc7180: Add bandwidth votes for eMMC
 and SDcard
In-Reply-To: <20200724171018.GZ3191083@google.com>
References: <1595328381-29552-1-git-send-email-sbhanu@codeaurora.org>
 <20200724171018.GZ3191083@google.com>
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On 2020-07-24 22:40, Matthias Kaehlcke wrote:
> Hi Shaik,
> 
> On Tue, Jul 21, 2020 at 04:16:21PM +0530, Shaik Sajida Bhanu wrote:
>> From: Pradeep P V K <ppvk@codeaurora.org>
>> 
>> Add the bandwidth domain supporting performance state and
>> the corresponding OPP tables for the sdhc device on sc7180.
>> 
>> Signed-off-by: Pradeep P V K <ppvk@codeaurora.org>
>> Signed-off-by: Shaik Sajida Bhanu <sbhanu@codeaurora.org>
>> ---
>> 
>> Changes since V1:
>> 	- Incorporated review comments by Bjorn Andersson.
>> ---
>>  arch/arm64/boot/dts/qcom/sc7180.dtsi | 15 +++++++++++++++
>>  1 file changed, 15 insertions(+)
>> 
>> diff --git a/arch/arm64/boot/dts/qcom/sc7180.dtsi 
>> b/arch/arm64/boot/dts/qcom/sc7180.dtsi
>> index 68f9894..d78a066 100644
>> --- a/arch/arm64/boot/dts/qcom/sc7180.dtsi
>> +++ b/arch/arm64/boot/dts/qcom/sc7180.dtsi
>> @@ -684,6 +684,9 @@
>>  			clocks = <&gcc GCC_SDCC1_APPS_CLK>,
>>  					<&gcc GCC_SDCC1_AHB_CLK>;
>>  			clock-names = "core", "iface";
>> +			interconnects = <&aggre1_noc MASTER_EMMC &mc_virt SLAVE_EBI1>,
>> +				<&gem_noc MASTER_APPSS_PROC &config_noc SLAVE_EMMC_CFG>;
>> +			interconnect-names = "sdhc-ddr","cpu-sdhc";
>>  			power-domains = <&rpmhpd SC7180_CX>;
>>  			operating-points-v2 = <&sdhc1_opp_table>;
>> 
>> @@ -704,11 +707,15 @@
>>  				opp-100000000 {
>>  					opp-hz = /bits/ 64 <100000000>;
>>  					required-opps = <&rpmhpd_opp_low_svs>;
>> +					opp-peak-kBps = <100000 100000>;
>> +					opp-avg-kBps = <100000 50000>;
>>  				};
>> 
>>  				opp-384000000 {
>>  					opp-hz = /bits/ 64 <384000000>;
>>  					required-opps = <&rpmhpd_opp_svs_l1>;
>> +					opp-peak-kBps = <600000 900000>;
>> +					opp-avg-kBps = <261438 300000>;
>>  				};
>>  			};
>>  		};
>> @@ -2476,6 +2483,10 @@
>>  			clocks = <&gcc GCC_SDCC2_APPS_CLK>,
>>  					<&gcc GCC_SDCC2_AHB_CLK>;
>>  			clock-names = "core", "iface";
>> +
>> +			interconnects = <&aggre1_noc MASTER_SDCC_2 &mc_virt SLAVE_EBI1>,
>> +				<&gem_noc MASTER_APPSS_PROC &config_noc	SLAVE_SDCC_2>;
>> +			interconnect-names = "sdhc-ddr","cpu-sdhc";
>>  			power-domains = <&rpmhpd SC7180_CX>;
>>  			operating-points-v2 = <&sdhc2_opp_table>;
>> 
>> @@ -2489,11 +2500,15 @@
>>  				opp-100000000 {
>>  					opp-hz = /bits/ 64 <100000000>;
>>  					required-opps = <&rpmhpd_opp_low_svs>;
>> +					opp-peak-kBps = <160000 100000>;
>> +					opp-avg-kBps = <80000 50000>;
>>  				};
>> 
>>  				opp-202000000 {
>>  					opp-hz = /bits/ 64 <202000000>;
>>  					required-opps = <&rpmhpd_opp_svs_l1>;
>> +					opp-peak-kBps = <200000	120000>;
>> +					opp-avg-kBps = <100000 60000>;
>>  				};
>>  			};
>>  		};
> 
> Does the sdhci-msm driver actually have BW scaling support at this 
> point?
> 

yes

> There is commit 4ece9795be56 ("mmc: sdhci-msm: Add interconnect
> bandwidth scaling support"), whose commit message says "make sure
> interconnect driver is ready before handling interconnect scaling.".
> 
> I haven't seen any patch adding the scaling support (supposedly by
> adding dev_pm_opp_set_bw() calls?). Did I miss it? If not it seems
> it would make sense to post it in a series together with this patch,
> as far as I can tell this patch alone does nothing in practical terms.
> 
> grep sdhc /sys/kernel/debug/interconnect/interconnect_summary
>   8804000.sdhci                          0            0            0
>   7c4000.sdhci                           0            0            0
>   7c4000.sdhci                           0            0            0
>   8804000.sdhci                          0            0            0
>   ...

"mmc: sdhci-msm: Use OPP API to set clk/perf 
state"(https://lkml.org/lkml/2020/4/8/425) and "mmc: sdhci-msm: Add 
interconnect bandwidth scaling 
support"(https://lkml.org/lkml/2020/3/12/60) with these two patches 
scaling will be supported for sdhci-msm driver.

the values  in  grep sdhc 
/sys/kernel/debug/interconnect/interconnect_summary will be zero during 
device is in suspend state... and the values in  grep sdhc 
/sys/kernel/debug/interconnect/interconnect_summary during device in 
resume state will be like the following::

cicalhost / # cat /sys/kernel/debug/interconnect/interconnect_summary | 
grep sdh
   8804000.sdhci                          0        60000       120000
   7c4000.sdhci                           0       300000       900000
   7c4000.sdhci                           0       300000       900000
   8804000.sdhci                          0        60000       120000
   8804000.sdhci                          0       100000       200000
   7c4000.sdhci                           0       261438       600000
   8804000.sdhci                          0        60000       120000