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From: Jie Gan <jie.gan@oss.qualcomm.com>
To: Bjorn Andersson <andersson@kernel.org>,
	Konrad Dybcio <konradybcio@kernel.org>,
	Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Mike Leach <mike.leach@linaro.org>,
	James Clark <james.clark@linaro.org>
Cc: linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] arm64: dts: qcom: qcs615: fix a crash issue caused by infinite loop for Coresight
Date: Thu, 22 May 2025 08:50:16 +0800	[thread overview]
Message-ID: <20250522005016.2148-1-jie.gan@oss.qualcomm.com> (raw)

An infinite loop has been created by the Coresight devices. When only a
source device is enabled, the coresight_find_activated_sysfs_sink function
is recursively invoked in an attempt to locate an active sink device,
ultimately leading to a stack overflow and system crash. Therefore, disable
the replicator1 to break the infinite loop and prevent a potential stack
overflow.

replicator1_out   ->   funnel_swao_in6   ->   tmc_etf_swao_in   ->  tmc_etf_swao_out
     |                                                                     |
replicator1_in                                                     replicator_swao_in
     |                                                                     |
replicator0_out1                                                   replicator_swao_out0
     |                                                                     |
replicator0_in                                                     funnel_in1_in3
     |                                                                     |
tmc_etf_out <- tmc_etf_in <- funnel_merg_out <- funnel_merg_in1 <- funnel_in1_out

[call trace]
   dump_backtrace+0x9c/0x128
   show_stack+0x20/0x38
   dump_stack_lvl+0x48/0x60
   dump_stack+0x18/0x28
   panic+0x340/0x3b0
   nmi_panic+0x94/0xa0
   panic_bad_stack+0x114/0x138
   handle_bad_stack+0x34/0xb8
   __bad_stack+0x78/0x80
   coresight_find_activated_sysfs_sink+0x28/0xa0 [coresight]
   coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight]
   coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight]
   coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight]
   coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight]
   ...
   coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight]
   coresight_enable_sysfs+0x80/0x2a0 [coresight]

side effect after the change:
Only trace data originating from AOSS can reach the ETF_SWAO and EUD sinks.

Fixes: bf469630552a ("arm64: dts: qcom: qcs615: Add coresight nodes")
Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/qcs615.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/qcom/qcs615.dtsi b/arch/arm64/boot/dts/qcom/qcs615.dtsi
index f08ba09772f3..b67c1f8a1118 100644
--- a/arch/arm64/boot/dts/qcom/qcs615.dtsi
+++ b/arch/arm64/boot/dts/qcom/qcs615.dtsi
@@ -1902,6 +1902,7 @@ replicator@604a000 {
 
 			clocks = <&aoss_qmp>;
 			clock-names = "apb_pclk";
+			status = "disabled";
 
 			in-ports {
 				port {
-- 
2.34.1


             reply	other threads:[~2025-05-22  0:50 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-05-22  0:50 Jie Gan [this message]
2025-05-22 15:06 ` [PATCH] arm64: dts: qcom: qcs615: fix a crash issue caused by infinite loop for Coresight Konrad Dybcio
2025-05-26  0:40   ` Jie Gan
2025-05-28 13:30     ` Mike Leach
2025-05-22 15:54 ` Suzuki K Poulose
2025-06-18  4:09 ` Bjorn Andersson

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