[igt-dev] [PATCH i-g-t 5/6] lib/igt_kmod: make it less pedantic with audio driver removal

[Mauro Carvalho Chehab]

From: Mauro Carvalho Chehab <mchehab at kernel.org>

Current Linux Kernel don't report if the audio driver binds
into the DRM driver. As this is CPU specific, allow audio
driver unload fail without skipping the IGT tests on legacy
Kernels, as this may not be mandatory.

On new kernels where lsmod will properly display de dependency
between the audio and DRM drivers, skip the core hotunplug
test if it fails to unload the audio driver, as this is is
unrelated to the DRM driver - and it could simply because there
are some userspace code using the audio device while the IGT
test is running.

Signed-off-by: Mauro Carvalho Chehab <mchehab at kernel.org>
---
 lib/igt_kmod.c         | 40 ++++++++++++++++++++++++++++++++--------
 tests/core_hotunplug.c |  7 ++-----
 2 files changed, 34 insertions(+), 13 deletions(-)

diff --git a/lib/igt_kmod.c b/lib/igt_kmod.c
index ab98b1cdefa5..d1d0662f3706 100644
--- a/lib/igt_kmod.c
+++ b/lib/igt_kmod.c
@@ -399,17 +399,32 @@ static int igt_always_unload_audio_driver(const char **who)
 		NULL,
 	};
 
+	/*
+	 * With old Kernels, the dependencies between audio and DRM drivers
+	 * are not shown. So, it may not be mandatory to remove the audio
+	 * driver before unload/unbind the DRM one. So, let's print warnings,
+	 * but return 0 on errors, as, if the dependency is mandatory, this
+	 * will be detected later when trying to unbind/unload the DRM driver.
+	 */
 	for (const char **m = sound; *m; m++) {
 		if (igt_kmod_is_loaded(*m)) {
 			if (who)
 				*who = *m;
-			if (igt_lsof_kill_audio_processes())
-				return 1;
+			if (igt_lsof_kill_audio_processes()) {
+				igt_warn("Could not stop audio process(es)\n");
+				igt_kmod_list_loaded();
+				igt_lsof("/dev/snd");
+				return 0;
+			}
 
 			kick_snd_hda_intel();
 			ret = igt_kmod_unload(*m, 0);
-			if (ret)
-				return ret;
+			if (ret) {
+				igt_warn("Could not unload audio driver %s\n", *m);
+				igt_kmod_list_loaded();
+				igt_lsof("/dev/snd");
+				return 0;
+			}
 		}
 	}
 	return 0;
@@ -547,6 +562,7 @@ static int linux_kernel_version(void)
 
 int igt_audio_driver_unload(const char **who)
 {
+	const char *drm_driver = "i915";
 	unsigned int num_mod, i, j;
 	struct module_ref *mod;
 	int pos = -1;
@@ -572,7 +588,7 @@ int igt_audio_driver_unload(const char **who)
 	mod = read_module_dependencies(&num_mod);
 
 	for (i = 0; i < num_mod; i++) {
-		if (!strcmp(mod[i].name, "i915")) {
+		if (!strcmp(mod[i].name, drm_driver)) {
 			break;
 		}
 	}
@@ -580,14 +596,15 @@ int igt_audio_driver_unload(const char **who)
 	if (i == num_mod)
 		return 0;
 
-	/* Recursively remove all drivers that depend on i915 */
+	/* Recursively remove all drivers that depend on the drm driver */
 	for (j = 0; j < mod[i].num_required; j++) {
 		pos = mod[i].required_by[j];
 		if (who)
 			*who = strdup(mod[pos].name);
 		/*
-		 * If a sound driver depends on i915, kill audio processes
-		 * first, in order to make it possible to unload the driver
+		 * If a sound driver depends on the drm driver, kill audio
+		 * processes first, in order to make it possible to unload
+		 * the driver.
 		 */
 		if (strstr(mod[pos].name, "snd")) {
 			if (igt_lsof_kill_audio_processes()) {
@@ -599,6 +616,13 @@ int igt_audio_driver_unload(const char **who)
 	}
 
 ret:
+	if (ret) {
+		igt_warn("Couldn't unload %s, which is using the %s driver\n",
+			 mod[pos].name, drm_driver);
+		igt_kmod_list_loaded();
+		igt_lsof("/dev/snd");
+	}
+
 	free_module_ref(mod, num_mod);
 
 	return ret;
diff --git a/tests/core_hotunplug.c b/tests/core_hotunplug.c
index 7c68b336e67b..3888c660d4ac 100644
--- a/tests/core_hotunplug.c
+++ b/tests/core_hotunplug.c
@@ -149,11 +149,8 @@ static void driver_unbind(struct hotunplug *priv, const char *prefix,
 	 * unbind i915 driver, reloading it when binding again.
 	 */
 	if (igt_audio_driver_unload(&priv->snd_driver)) {
-		if (priv->snd_driver)
-			igt_warn("Could not unload audio driver %s\n", priv->snd_driver);
-		igt_kmod_list_loaded();
-		igt_lsof("/dev/snd");
-		igt_skip("Audio is in use, skipping\n");
+		igt_skip("Audio driver %s in use, skipping test\n",
+			 priv->snd_driver);
 	} else if (priv->snd_driver) {
 		igt_info("Unloaded audio driver %s\n", priv->snd_driver);
 	}
-- 
2.35.1