[PATCH 4/4] drm/i915: add new param to force audio on or off for HDMI/DP port

[Zhenyu Wang]

Two reasons to add this param, one is for some AV device requiring
HDMI input for audio, but some device might not have sane EDID info
to enable audio on HDMI port. Another is for testing purpose.

Signed-off-by: Zhenyu Wang <zhenyuw at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c   |    3 +++
 drivers/gpu/drm/i915/i915_drv.h   |    1 +
 drivers/gpu/drm/i915/intel_dp.c   |    3 ++-
 drivers/gpu/drm/i915/intel_hdmi.c |    3 ++-
 4 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index dffc1bc..95277e5 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -48,6 +48,9 @@ module_param_named(powersave, i915_powersave, int, 0400);
 unsigned int i915_lvds_downclock = 0;
 module_param_named(lvds_downclock, i915_lvds_downclock, int, 0400);
 
+unsigned int i915_force_audio = -1;
+module_param_named(force_audio, i915_force_audio, int, 0400);
+
 static struct drm_driver driver;
 extern int intel_agp_enabled;
 
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b0692c4..495182e 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -844,6 +844,7 @@ extern int i915_max_ioctl;
 extern unsigned int i915_fbpercrtc;
 extern unsigned int i915_powersave;
 extern unsigned int i915_lvds_downclock;
+extern unsigned int i915_force_audio;
 
 extern int i915_suspend(struct drm_device *dev, pm_message_t state);
 extern int i915_resume(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 81fca1e..77b45e7 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -736,7 +736,8 @@ intel_dp_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode,
 		intel_dp->DP |= DP_PORT_WIDTH_4;
 		break;
 	}
-	if (intel_dp->has_audio)
+	if (i915_force_audio == 1 ||
+	    (i915_force_audio != 0 && intel_dp->has_audio))
 		intel_dp->DP |= DP_AUDIO_OUTPUT_ENABLE;
 
 	memset(intel_dp->link_configuration, 0, DP_LINK_CONFIGURATION_SIZE);
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 90184e6..20af171 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -76,7 +76,8 @@ static void intel_hdmi_mode_set(struct drm_encoder *encoder,
 	if (intel_hdmi->has_hdmi_sink && HAS_PCH_CPT(dev))
 		sdvox |= HDMI_MODE_SELECT;
 
-	if (intel_hdmi->has_audio)
+	if (i915_force_audio == 1 ||
+	    (i915_force_audio != 0 && intel_hdmi->has_audio))
 		sdvox |= SDVO_AUDIO_ENABLE;
 
 	if (intel_crtc->pipe == 1) {
-- 
1.7.1