[igt-dev] [PATCH i-g-t v6 21/24] tests/core_hotunplug: HSW/BDW audio issue workaround

[Janusz Krzysztofik]

Unbinding the i915 driver on some Haswell and Broadwell platforms with
Azalia audio results in a kernel WARNING on "i915 raw-wakerefs=1
wakelocks=1 on cleanup".  The issue can be worked around by manually
enabling runtime power management for the conflicting audio adapter.
Use that method but also display a warning to preserve visibility of
the issue.  Also tag the workaround with a FIXME comment.

v2: Extend the scope of the workaround over Broadwell

Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik at linux.intel.com>
---
 tests/core_hotunplug.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/tests/core_hotunplug.c b/tests/core_hotunplug.c
index ac106d964..3e2a76ddb 100644
--- a/tests/core_hotunplug.c
+++ b/tests/core_hotunplug.c
@@ -484,8 +484,23 @@ igt_main
 		igt_skip_on_f(fd_drm < 0, "No known DRM device found\n");
 
 		if (is_i915_device(fd_drm)) {
+			uint32_t devid = intel_get_drm_devid(fd_drm);
+
 			gem_quiescent_gpu(fd_drm);
 			igt_require_gem(fd_drm);
+
+			/**
+			 * FIXME: Unbinding the i915 driver on some Haswell
+			 * platforms with Azalia audio results in a kernel WARN
+			 * on "i915 raw-wakerefs=1 wakelocks=1 on cleanup".  The
+			 * below CI friendly user level workaround prevents the
+			 * warning from appearing.  Drop this hack as soon as
+			 * this is fixed in the kernel.
+			 */
+			if (igt_warn_on_f(IS_HASWELL(devid) ||
+					  IS_BROADWELL(devid),
+			    "Manually enabling audio PM to work around a kernel WARN\n"))
+				igt_pm_enable_audio_runtime_pm();
 		}
 
 		/* Make sure subtests always reopen the same device */
-- 
2.21.1