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From: Reza Kurniawan <imkyufie@gmail.com>
To: Mark Rutland <mark.rutland@arm.com>,
	 Lorenzo Pieralisi <lpieralisi@kernel.org>,
	Rob Herring <robh@kernel.org>,
	 Krzysztof Kozlowski <krzk+dt@kernel.org>,
	 Conor Dooley <conor+dt@kernel.org>,
	Ulf Hansson <ulfh@kernel.org>,
	 "Rafael J. Wysocki" <rafael@kernel.org>,
	 Daniel Lezcano <daniel.lezcano@kernel.org>,
	 Christian Loehle <christian.loehle@arm.com>,
	 Bjorn Andersson <andersson@kernel.org>,
	 Konrad Dybcio <konradybcio@kernel.org>,
	Abel Vesa <abelvesa@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
	 linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	 linux-arm-msm@vger.kernel.org,
	Reza Kurniawan <imkyufie@gmail.com>
Subject: [PATCH 4/4] arm64: dts: qcom: msm8917: Use a shallower cluster state to fix unresponsive idle
Date: Sat, 17 Oct 2026 23:41:26 +0700	[thread overview]
Message-ID: <20261017-psci-fix-v1-4-dedae27e4a31@gmail.com> (raw)
In-Reply-To: <20261017-psci-fix-v1-0-dedae27e4a31@gmail.com>

MSM8917 is a single cluster SoC, so powering down the cluster means
powering down the whole system. This causes two problems:

1. The system becomes unresponsive, even to common interrupts. Waking it
   requires an interrupt from the MPM (MSM Power Manager) or scheduling
   the MPM to wake the system later. Linux currently has no way of doing
   the latter, so the cluster may never resume operation.

2. Entering power collapse blanks the screen. When the state is entered
   and exited repeatedly, this shows up as visible flicker.

Even if MPM scheduling were implemented, the second problem would remain
and it wouldn't fix the system being unresponsive at idle.

Replace the idle state with PSCI mode 4 (dubbed GDHS downstream), which
is less aggressive and can wake up from conventional interrupt sources.

Signed-off-by: Reza Kurniawan <imkyufie@gmail.com>
---
 arch/arm64/boot/dts/qcom/msm8917.dtsi | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/msm8917.dtsi b/arch/arm64/boot/dts/qcom/msm8917.dtsi
index f0771187d0..7730977e6e 100644
--- a/arch/arm64/boot/dts/qcom/msm8917.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8917.dtsi
@@ -112,10 +112,10 @@ core3 {
 		domain-idle-states {
 			cluster_sleep_0: cluster-sleep-0 {
 				compatible = "domain-idle-state";
-				arm,psci-suspend-param = <0x41000053>;
-				entry-latency-us = <700>;
-				exit-latency-us = <1000>;
-				min-residency-us = <6500>;
+				arm,psci-suspend-param = <0x41000043>;
+				entry-latency-us = <240>;
+				exit-latency-us = <280>;
+				min-residency-us = <806>;
 			};
 		};
 

-- 
2.55.0


      parent reply	other threads:[~2026-10-17 16:43 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-17 16:41 [PATCH 0/4] Fix PSCI on MSM8917 and MSM8937 Reza Kurniawan
2026-10-17 16:41 ` [PATCH 1/4] dt-bindings: arm: psci: Add skip-suspend-mode-switch property Reza Kurniawan
2026-10-17 16:41 ` [PATCH 2/4] cpuidle: psci: Allow skipping the suspend mode switch Reza Kurniawan
2026-10-17 16:41 ` [PATCH 3/4] arm64: dts: qcom: Skip suspend mode switch on MSM8917 and MSM8937 Reza Kurniawan
2026-10-17 16:41 ` Reza Kurniawan [this message]

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