[igt-dev] [PATCH v4] Chamelium: Get Chamelium Logs on RPC failure

[Mark Yacoub <markyacoub@chromium.org>]

From: Mark Yacoub <markyacoub@chromium.org>

[Why]
Currently, Chamelium acts like a black box, we can't tell what
is going on there when a failure occur. Seeing its logs will
allow us to debug better.

[How]
On chamelium_rpc failure, print out the logs in debug so it
wouldn't clutter good tests.

v2:
- Added missing #includes
v3:
- C-style comments (Kamil Konieczny)
- Cut commit messages to 65 char tops (Kamil Konieczny)
v4:
- Don't get the logs if it's not a cv3 (Petri)
v5:
- Fix comments style (Kamil)

Signed-off-by: Mark Yacoub <markyacoub@chromium.org>
---
 lib/igt_chamelium.c                    | 73 ++++++++++++++++++++++++--
 lib/igt_chamelium.h                    |  1 +
 tests/chamelium/kms_chamelium_helper.c | 18 +++++++
 3 files changed, 89 insertions(+), 3 deletions(-)

diff --git a/lib/igt_chamelium.c b/lib/igt_chamelium.c
index a235f3c8..f6df2098 100644
--- a/lib/igt_chamelium.c
+++ b/lib/igt_chamelium.c
@@ -129,6 +129,9 @@ struct chamelium {
 	struct igt_list_head edids;
 	struct chamelium_port ports[CHAMELIUM_MAX_PORTS];
 	int port_count;
+	/* Chamelium V3 requires some work arounds and has some extra
+	   functionalities. This keeps things safe. */
+	bool is_cv3;
 };
 
 bool igt_chamelium_allow_fsm_handling = true;
@@ -447,6 +450,9 @@ chamelium_wait_for_conn_status_change(igt_display_t *display,
 		usleep(50000);
 	}
 
+	/* If we timeout, it means Chamelium didn't respond on time. Print its logs*/
+	igt_debug("Timeout. Chamelium logs:\n%s\n", chamelium_get_logs(chamelium));
+
 	igt_assert_f(false, "Timed out waiting for %s to get %s\n",
 				 chamelium_port_get_name(port),
 				 kmstest_connector_status_str(status));
@@ -658,6 +664,8 @@ static xmlrpc_value *chamelium_rpc(struct chamelium *chamelium,
 	xmlrpc_value *res;
 	va_list va_args;
 	int fsm_trials_left = 5;
+	bool did_fault_occur = false;
+	char fault_string[1024];
 
 	if (strcmp(method_name, "CaptureVideo") == 0
 	    || strcmp(method_name, "StartCapturingVideo") == 0) {
@@ -680,9 +688,35 @@ static xmlrpc_value *chamelium_rpc(struct chamelium *chamelium,
 					 format_str, va_args);
 		va_end(va_args);
 	}
-	igt_assert_f(!chamelium->env.fault_occurred,
-		     "Chamelium RPC call[%s] failed: %s\n", method_name,
-		     chamelium->env.fault_string);
+
+	did_fault_occur = chamelium->env.fault_occurred;
+	if (did_fault_occur) {
+		/*
+		 * Save the fault string before getting the logs which will
+		 * clear the string if it is works.
+		 */
+		strncpy(fault_string, chamelium->env.fault_string, 1024);
+
+		if (strcmp(method_name, "GetChameleondLogs") == 0) {
+			did_fault_occur = false;
+			igt_debug("Failed to get chamelium logs: %s\n", fault_string);
+			igt_debug("Sometimes this happens at the beginning of the test when the logs haven't "
+			"been cleared for a while and the XMLRPC lib can't consume it all. "
+			"Regardless, we shouldn't fail on failing to get the logs.\n");
+			/*
+			 * We call GetChameleondLogs on an xmlrpc failure. Let's not
+			 * call it when the xmlrpc failure is for GetChameleondLogs
+			 * itself as this can cause a recursive behavior.
+			 */
+		} else {
+			char *logs = chamelium_get_logs(chamelium);
+			igt_debug("CHAMELIUM LOGS:\n%s\n", logs);
+			free(logs);
+		}
+	}
+
+	igt_assert_f(!did_fault_occur, "Chamelium RPC call [%s] failed: %s\n",
+		     method_name, fault_string);
 
 	return res;
 }
@@ -737,6 +771,33 @@ void chamelium_assert_reachable(struct chamelium *chamelium, int timeout)
 		     "Couldn't connect to Chamelium for %ds", timeout);
 }
 
+/**
+ * chamelium_get_logs - Get the logs from the chamelium daemon
+ * @chamelium: The Chamelium instance to use
+ *
+ * Returns: The logs from the last time this was called.
+ */
+
+const char *chamelium_get_logs(struct chamelium *chamelium)
+{
+	xmlrpc_value *res;
+	const char *logs = NULL;
+
+	if (!chamelium->is_cv3) {
+		igt_debug("Chamelium is not a Cv3, not calling GetChameleondLogs\n");
+		return NULL;
+	}
+
+	igt_debug("Calling GetChameleondLogs - Logs returned are from the last "
+		  "time this was called.\n");
+
+	res = chamelium_rpc(chamelium, NULL, "GetChameleondLogs", "(s)", "IGT");
+	xmlrpc_read_string(&chamelium->env, res, &logs);
+	xmlrpc_DECREF(res);
+
+	return logs;
+}
+
 /**
  * chamelium_plug:
  * @chamelium: The Chamelium instance to use
@@ -2890,6 +2951,7 @@ struct chamelium *chamelium_init(int drm_fd, igt_display_t *display)
 {
 	struct chamelium *chamelium = chamelium_init_rpc_only();
 	bool mismatching_ports_found = false;
+	int port_ids[CHAMELIUM_MAX_PORTS];
 
 	if (chamelium == NULL)
 		return NULL;
@@ -2958,6 +3020,11 @@ struct chamelium *chamelium_init(int drm_fd, igt_display_t *display)
 	 * the outputs to grab all supported connectors.*/
 	igt_display_reset_outputs(display);
 
+	if (chamelium_get_video_ports(chamelium, port_ids) <= 0)
+		goto error;
+	/* Chamelium V3 port IDs start with 0, while V2 port IDs start with 1. */
+	chamelium->is_cv3 = port_ids[0] == 0;
+
 	return chamelium;
 error:
 	close(chamelium->drm_fd);
diff --git a/lib/igt_chamelium.h b/lib/igt_chamelium.h
index d979de4a..159c75ec 100644
--- a/lib/igt_chamelium.h
+++ b/lib/igt_chamelium.h
@@ -159,6 +159,7 @@ chamelium_reset_state(igt_display_t *display,
 
 bool chamelium_wait_reachable(struct chamelium *chamelium, int timeout);
 void chamelium_assert_reachable(struct chamelium *chamelium, int timeout);
+const char *chamelium_get_logs(struct chamelium *chamelium);
 void chamelium_plug(struct chamelium *chamelium, struct chamelium_port *port);
 void chamelium_unplug(struct chamelium *chamelium, struct chamelium_port *port);
 bool chamelium_is_plugged(struct chamelium *chamelium,
diff --git a/tests/chamelium/kms_chamelium_helper.c b/tests/chamelium/kms_chamelium_helper.c
index 197d29be..54f8ebfc 100644
--- a/tests/chamelium/kms_chamelium_helper.c
+++ b/tests/chamelium/kms_chamelium_helper.c
@@ -24,7 +24,19 @@
  *    Lyude Paul <lyude@redhat.com>
  */
 
+#include <fcntl.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdatomic.h>
+#include <xf86drmMode.h>
+
+#include "config.h"
+#include "igt.h"
+#include "igt_chamelium.h"
 #include "igt_edid.h"
+#include "igt_eld.h"
+#include "igt_vc4.h"
+#include "igt_infoframe.h"
 #include "kms_chamelium_helper.h"
 
 void chamelium_init_test(chamelium_data_t *data)
@@ -47,6 +59,12 @@ void chamelium_init_test(chamelium_data_t *data)
 	/* we need to initalize chamelium after igt_display_require */
 	data->chamelium = chamelium_init(data->drm_fd, &data->display);
 	igt_require(data->chamelium);
+	/*
+	 * Get the logs so we can reset the chamelium logs at this cursor.
+	 * The logs are then retrieved when any call fails so we can debug
+	 * chamelium if needed.
+	 */
+	free(chamelium_get_logs(data->chamelium));
 
 	data->ports = chamelium_get_ports(data->chamelium, &data->port_count);
 
-- 
2.39.1.519.gcb327c4b5f-goog