Re: [PATCH V2] arm64: dts: qcom: sc7180: Add bandwidth votes for eMMC and SDcard

From: Matthias Kaehlcke
Date: Wed Aug 12 2020 - 11:15:21 EST

On Wed, Aug 12, 2020 at 04:26:08PM +0530, sbhanu@xxxxxxxxxxxxxx wrote:
> On 2020-08-11 22:38, Matthias Kaehlcke wrote:
> > On Tue, Jul 28, 2020 at 04:49:05PM +0530, sbhanu@xxxxxxxxxxxxxx wrote:
> > > On 2020-07-28 00:40, Matthias Kaehlcke wrote:
> > > > Hi,
> > > >
> > > > On Mon, Jul 27, 2020 at 12:20:38PM +0530, sbhanu@xxxxxxxxxxxxxx wrote:
> > > > > 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@xxxxxxxxxxxxxx>
> > > > > > >
> > > > > > > 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@xxxxxxxxxxxxxx>
> > > > > > > Signed-off-by: Shaik Sajida Bhanu <sbhanu@xxxxxxxxxxxxxx>
> > > > > > > ---
> > > > > > >
> > > > > > > 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.
> > > >
> > > > Are you testing with exactly these patches or with the ones that landed
> > > > upstream? At least the second one changed substantially
> > > >
> > > > > the values in grep sdhc
> > > > > /sys/kernel/debug/interconnect/interconnect_summary will be zero
> > > > > during
> > > > > device is in suspend state...
> > > >
> > > > Yes, I forgot to mention that I started MMC IO before looking at
> > > > 'interconnect_summary'.
> > > >
> > > > > 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
> > > >
> > > > On my system the bandwidth is never set:
> > > >
> > > > 3.590152] sdhci_msm 7c4000.sdhci: DBG: old/new frequencies (384000000
> > > > Hz) are same, nothing to do
> > > > https://elixir.bootlin.com/linux/v5.7.8/source/drivers/opp/core.c#L847
> > > >
> > > > This happens every time, even after the bandwith is set to 0. The
> > > > problem
> > > > seems to be that opp_table->clk doesn't change for target_freq = 0.
> > > >
> > > > My system is based on v5.4, so it is possible that my kernel is missing
> > > > some
> > > > relevant patch from upstream.
> > > Hi matthias,
> > >
> > > In order to aviod confusion this patch is continuation of the below
> > > patch::
> > > "mmc: sdhci-msm: Add interconnect bandwidth scaling support"
> > > (https://lkml.org/lkml/2020/6/9/160).
> >
> > My kernel contains this patch.
> >
> > As you told me in private, the patch "opp: Fix dev_pm_opp_set_rate()
> > to not return early" (https://patchwork.kernel.org/patch/11707003/) is
> > needed, which fixes exactly the problem I described.
> >
> > It seems the tree you tested was not based on the maintainer tree or
> > upstream,
> > please make that clear when someone reports issues. Since you said it
> > works
> > for you I wasted time trying to chase down a missing patch which did not
> > exist
> > (yet).
>
>
> Hi Matthis,
>
> Can you confirm from your end the issue that you reported got fixed
> with Rajendra patch or not. Once you confirm, I can ask Bjorn to pull
> this dt change.

Yes, the issue is fixed with Rajendra's patch

Tested-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>