Thread (5 messages) 5 messages, 3 authors, 9d ago

Re: [PATCH] usb: typec: add trace point for typec_set_mode

From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Date: 2026-06-18 10:56:47
Also in: linux-usb, lkml

Hi Ahmad,

On Wed, Jun 17, 2026 at 10:03:04PM +0200, Ahmad Fatoum wrote:
quoted hunk ↗ jump to hunk
Some Type-C controllers toggle muxes themselves. Other controllers like
the TUSB320 report the mode to the host, so it can control the muxes.

To improve debuggability of both kinds of drivers, add a trace point that
can be used to keep track of the mode being set inside the Type-C
framework:

  echo 1 > /sys/kernel/debug/tracing/events/typec/typec_mode/enable

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 MAINTAINERS                  |  1 +
 drivers/usb/typec/class.c    |  9 ++++++++-
 include/trace/events/typec.h | 36 ++++++++++++++++++++++++++++++++++++
 3 files changed, 45 insertions(+), 1 deletion(-)
diff --git a/MAINTAINERS b/MAINTAINERS
index c8d4b913f26c..ddd59e5e6eaf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -27753,6 +27753,7 @@ F:	Documentation/ABI/testing/sysfs-class-typec
 F:	Documentation/driver-api/usb/typec.rst
 F:	drivers/usb/typec/
 F:	include/linux/usb/typec.h
+F:	include/trace/events/typec*.h
 
 USB TYPEC INTEL PMC MUX DRIVER
 M:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
index 0977581ad1b6..9316d067f19a 100644
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -20,6 +20,9 @@
 #include "class.h"
 #include "pd.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/typec.h>
Those should probable go to drivers/usb/typec/trace.c and then you
need add something like this to drivers/usb/typec/Makefile:

 obj-$(CONFIG_TYPEC)            += typec.o
 typec-y                                := class.o mux.o bus.o pd.o retimer.o mode_selection.o
 typec-$(CONFIG_ACPI)           += port-mapper.o
+typec-$(CONFIG_TRACING)                += trace.o
 obj-$(CONFIG_TYPEC)            += altmodes/
 obj-$(CONFIG_TYPEC_TCPM)       += tcpm/
 obj-$(CONFIG_TYPEC_UCSI)       += ucsi/


Thanks,

-- 
heikki
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