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arm64: dts: qcom: qcs615: fix a crash issue caused by infinite loop for Coresight

Message ID 20250522005016.2148-1-jie.gan@oss.qualcomm.com
State New
Headers show
Series arm64: dts: qcom: qcs615: fix a crash issue caused by infinite loop for Coresight | expand

Commit Message

Jie Gan May 22, 2025, 12:50 a.m. UTC 
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(+)
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Patch

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 {