lib/pm: Wait a little for sound module load to complete

Sometimes we may probe the sound module as it is still being registered
and its debugfs not yet fully populated. If we do not find a file we
expect to exist, sleep a little and check again.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107801
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.linux.com>
Reviewed-by: Imre Deak <imre.deak@intel.linux.com>

1 files changed, 15 insertions, 7 deletions

diff --git a/lib/igt_pm.c b/lib/igt_pm.c
index b1f359d8..e86fa4a4 100644
--- a/lib/igt_pm.c
+++ b/lib/igt_pm.c
@@ -154,20 +154,28 @@ static int __igt_pm_enable_audio_runtime_pm(void)
 	while ((de = readdir(dir))) {
 		const char *match = "hwC";
 		char buf[32] = { }; /* for Valgrind */
-		char *tmp;
+		int loops = 500;
+		int base;
 		int ret;
 
 		if (de->d_type != DT_LNK ||
 		    strncmp(de->d_name, match, strlen(match)))
 			continue;
 
-		igt_assert(asprintf(&tmp,
-				    "/sys/class/sound/%s/vendor_name",
-				    de->d_name));
+		base = openat(dirfd(dir), de->d_name, O_RDONLY);
+		igt_assert_fd(base);
+
+		do {
+			fd = openat(base, "vendor_name", O_RDONLY);
+			if (fd < 0) /* module is still loading? */
+				usleep(1000);
+			else
+				break;
+		} while (--loops);
+		close(base);
+		if (fd < 0)
+			continue;
 
-		fd = open(tmp, O_RDONLY);
-		free(tmp);
-		igt_assert_fd(fd);
 		ret = read(fd, buf, sizeof(buf));
 		close(fd);
 		igt_assert(ret > 0);