[PATCH v2] coresight: Disable MMIO logging for coresight stm driver

[Mao Jinlong]

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 at quicinc.com>
Reviewed-by: Leo Yan <leo.yan at arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual at 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