With MMIO logging enabled, the MMIO access are traced and could be
sent to an STM device. Thus, an STM driver MMIO access could create
circular call chain with MMIO logging. Disable it for STM driver.

[] stm_source_write[stm_core]+0xc4
[] stm_ftrace_write[stm_ftrace]+0x40
[] trace_event_buffer_commit+0x238
[] trace_event_raw_event_rwmmio_rw_template+0x8c
[] log_post_write_mmio+0xb4
[] writel_relaxed[coresight_stm]+0x80
[] stm_generic_packet[coresight_stm]+0x1a8
[] stm_data_write[stm_core]+0x78
[] stm_source_write[stm_core]+0x7c
[] stm_ftrace_write[stm_ftrace]+0x40
[] trace_event_buffer_commit+0x238
[] trace_event_raw_event_rwmmio_read+0x84
[] log_read_mmio+0xac
[] readl_relaxed[coresight_tmc]+0x50

Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Reviewed-by: Leo Yan <leo.yan@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
Changes in V2:
update the commit message

 drivers/hwtracing/coresight/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index 4ba478211b31..f3158266f75e 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -22,6 +22,8 @@ condflags := \
 	$(call cc-option, -Wstringop-truncation)
 subdir-ccflags-y += $(condflags)
 
+CFLAGS_coresight-stm.o := -D__DISABLE_TRACE_MMIO__
+
 obj-$(CONFIG_CORESIGHT) += coresight.o
 coresight-y := coresight-core.o  coresight-etm-perf.o coresight-platform.o \
 		coresight-sysfs.o coresight-syscfg.o coresight-config.o \
-- 
2.25.1

On Tue, 06 May 2025 00:57:43 -0700, Mao Jinlong wrote:
> With MMIO logging enabled, the MMIO access are traced and could be
> sent to an STM device. Thus, an STM driver MMIO access could create
> circular call chain with MMIO logging. Disable it for STM driver.
> 
> [] stm_source_write[stm_core]+0xc4
> [] stm_ftrace_write[stm_ftrace]+0x40
> [] trace_event_buffer_commit+0x238
> [] trace_event_raw_event_rwmmio_rw_template+0x8c
> [] log_post_write_mmio+0xb4
> [] writel_relaxed[coresight_stm]+0x80
> [] stm_generic_packet[coresight_stm]+0x1a8
> [] stm_data_write[stm_core]+0x78
> [] stm_source_write[stm_core]+0x7c
> [] stm_ftrace_write[stm_ftrace]+0x40
> [] trace_event_buffer_commit+0x238
> [] trace_event_raw_event_rwmmio_read+0x84
> [] log_read_mmio+0xac
> [] readl_relaxed[coresight_tmc]+0x50
> 
> [...]

Applied, thanks!

[1/1] coresight: Disable MMIO logging for coresight stm driver
      https://git.kernel.org/coresight/c/6264f1df

Best regards,
-- 
Suzuki K Poulose <suzuki.poulose@arm.com>