Re: [PATCH v2 00/11] Add GPLL0 as clock provider for the Qualcomm's IPQ mailbox controller

From: Kathiravan Thirumoorthy
Date: Wed Oct 18 2023 - 10:10:14 EST



On 9/14/2023 12:29 PM, Kathiravan Thirumoorthy wrote:
Currently mailbox controller takes the XO and APSS PLL as the input. It
can take the GPLL0 also as an input. This patch series adds the same and
fixes the issue caused by this.

Once the cpufreq driver is up, it tries to bump up the cpu frequency
above 800MHz, while doing so system is going to unusable state. Reason
being, with the GPLL0 included as clock source, clock framework tries to
achieve the required rate with the possible parent and since GPLL0
carries the CLK_SET_RATE_PARENT flag, clock rate of the GPLL0 is getting
changed, causing the issue.

First half of the series, removes the CLK_SET_RATE_PARENT flag from the
PLL clocks since the PLL clock rates shouldn't be changed. Another
half, add the necessary support to include the GPLL0 as clock provider
for mailbox and accomodate the changes in APSS clock driver.

This is also the preparatory series to enable the CPUFreq on IPQ5332
SoC. Dynamic scaling of CPUFreq is not supported on IPQ5332, so to
switch between the frequencies we need to park the APSS PLL in safe
source, here it is GPLL0 and then shutdown and bring up the APSS PLL in
the desired rate.

For IPQ5332 SoC, this series depends on the below patch
https://lore.kernel.org/linux-arm-msm/1693474133-10467-1-git-send-email-quic_varada@xxxxxxxxxxx/


Bjorn, can this series picked up for v6.7?

There is a minor nit the commit message. The statement "APSS PLL will be running at 800MHz" should be "APSS clock / CPU clock will be running at 800MHz" and this should be taken care for clk and the dts patches. Do let me know if I need to re-spin the address to address this.

Thanks,



Signed-off-by: Kathiravan Thirumoorthy <quic_kathirav@xxxxxxxxxxx>
---
Changes in v2:
- included the patch to drop the CLK_SET_RATE_PARENT from IPQ5018 GCC driver
- Splitted the DTS changes per target
- For IPQ8074 and IPQ6018 keep the CLK_SET_RATE_PARENT for UBI32 PLL
since the PLL clock rates can be changed
- Pick up the tags in the relevant patches
- Link to v1: https://lore.kernel.org/r/20230904-gpll_cleanup-v1-0-de2c448f1188@xxxxxxxxxxx

---
Kathiravan Thirumoorthy (11):
clk: qcom: ipq8074: drop the CLK_SET_RATE_PARENT flag from PLL clocks
clk: qcom: ipq6018: drop the CLK_SET_RATE_PARENT flag from PLL clocks
clk: qcom: ipq5018: drop the CLK_SET_RATE_PARENT flag from GPLL clocks
clk: qcom: ipq9574: drop the CLK_SET_RATE_PARENT flag from GPLL clocks
clk: qcom: ipq5332: drop the CLK_SET_RATE_PARENT flag from GPLL clocks
dt-bindings: mailbox: qcom: add one more clock provider for IPQ mailbox
clk: qcom: apss-ipq6018: add the GPLL0 clock also as clock provider
arm64: dts: qcom: ipq8074: include the GPLL0 as clock provider for mailbox
arm64: dts: qcom: ipq6018: include the GPLL0 as clock provider for mailbox
arm64: dts: qcom: ipq9574: include the GPLL0 as clock provider for mailbox
arm64: dts: qcom: ipq5332: include the GPLL0 as clock provider for mailbox

.../devicetree/bindings/mailbox/qcom,apcs-kpss-global.yaml | 2 ++
arch/arm64/boot/dts/qcom/ipq5332.dtsi | 4 ++--
arch/arm64/boot/dts/qcom/ipq6018.dtsi | 4 ++--
arch/arm64/boot/dts/qcom/ipq8074.dtsi | 4 ++--
arch/arm64/boot/dts/qcom/ipq9574.dtsi | 4 ++--
drivers/clk/qcom/apss-ipq6018.c | 3 +++
drivers/clk/qcom/gcc-ipq5018.c | 3 ---
drivers/clk/qcom/gcc-ipq5332.c | 2 --
drivers/clk/qcom/gcc-ipq6018.c | 6 ------
drivers/clk/qcom/gcc-ipq8074.c | 6 ------
drivers/clk/qcom/gcc-ipq9574.c | 4 ----
11 files changed, 13 insertions(+), 29 deletions(-)
---
base-commit: e143016b56ecb0fcda5bb6026b0a25fe55274f56
change-id: 20230913-gpll_cleanup-5d0a339ebd17

Best regards,