[PATCH] coresight: Disable MMIO logging for coresight stm driver

[Mao Jinlong]

When read/write registers with readl_relaxed and writel_relaxed,
log_read_mmio and log_write_mmio will be called. If mmio trace
is enabled to STM, STM driver will write the register to send the
trace and writel_relaxed will be called again. The circular call
like callstack below will happen. Disable mmio logging for stm
driver to avoid this issue.

[] 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
[] ost_write[stm_p_ost]+0xc8
[] 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 at quicinc.com>
---
 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