It is helpful to trace the channel setting for the multichannel isochronous
context when the core function is requested it by both in-kernel unit
drivers and userspace applications.

This commit adds some tracepoints events for the aim.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
---
 drivers/firewire/core-iso.c     |  2 ++
 include/trace/events/firewire.h | 21 +++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/drivers/firewire/core-iso.c b/drivers/firewire/core-iso.c
index ddb999297c72..7ec84de846e6 100644
--- a/drivers/firewire/core-iso.c
+++ b/drivers/firewire/core-iso.c
@@ -177,6 +177,8 @@ EXPORT_SYMBOL(fw_iso_context_start);
 
 int fw_iso_context_set_channels(struct fw_iso_context *ctx, u64 *channels)
 {
+	trace_isoc_inbound_multiple_channels(ctx, *channels);
+
 	return ctx->card->driver->set_iso_channels(ctx, channels);
 }
 
diff --git a/include/trace/events/firewire.h b/include/trace/events/firewire.h
index 0cca1ef841f3..0334e02f9d94 100644
--- a/include/trace/events/firewire.h
+++ b/include/trace/events/firewire.h
@@ -541,6 +541,27 @@ DEFINE_EVENT_CONDITION(isoc_destroy_template, isoc_inbound_multiple_destroy,
 	TP_CONDITION(ctx->type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL)
 );
 
+TRACE_EVENT(isoc_inbound_multiple_channels,
+	TP_PROTO(const struct fw_iso_context *ctx, u64 channels),
+	TP_ARGS(ctx, channels),
+	TP_STRUCT__entry(
+		__field(u64, context)
+		__field(u8, card_index)
+		__field(u64, channels)
+	),
+	TP_fast_assign(
+		__entry->context = (uintptr_t)ctx;
+		__entry->card_index = ctx->card->index;
+		__entry->channels = channels;
+	),
+	TP_printk(
+		"context=0x%llx card_index=%u channels=0x%016llx",
+		__entry->context,
+		__entry->card_index,
+		__entry->channels
+	)
+);
+
 #undef QUADLET_SIZE
 
 #endif // _FIREWIRE_TRACE_EVENT_H
-- 
2.43.0