3 files changed, 70 insertions, 5 deletions

diff --git a/drivers/gpu/drm/msm/dp/dp_audio.c b/drivers/gpu/drm/msm/dp/dp_audio.c
index 11fa5ad7a801..82a8673ab8da 100644
--- a/drivers/gpu/drm/msm/dp/dp_audio.c
+++ b/drivers/gpu/drm/msm/dp/dp_audio.c
@@ -497,8 +497,23 @@ int dp_audio_hw_params(struct device *dev,
 	int rc = 0;
 	struct dp_audio_private *audio;
 	struct platform_device *pdev;
+	struct msm_dp *dp_display;
 
 	pdev = to_platform_device(dev);
+	dp_display = platform_get_drvdata(pdev);
+
+	/*
+	 * there could be cases where sound card can be opened even
+	 * before OR even when DP is not connected . This can cause
+	 * unclocked access as the audio subsystem relies on the DP
+	 * driver to maintain the correct state of clocks. To protect
+	 * such cases check for connection status and bail out if not
+	 * connected.
+	 */
+	if (!dp_display->power_on) {
+		rc = -EINVAL;
+		goto end;
+	}
 
 	audio = dp_audio_get_data(pdev);
 	if (IS_ERR(audio)) {
@@ -512,6 +527,8 @@ int dp_audio_hw_params(struct device *dev,
 	dp_audio_setup_acr(audio);
 	dp_audio_safe_to_exit_level(audio);
 	dp_audio_enable(audio, true);
+	dp_display->audio_enabled = true;
+
 end:
 	return rc;
 }
@@ -520,15 +537,30 @@ static void dp_audio_shutdown(struct device *dev, void *data)
 {
 	struct dp_audio_private *audio;
 	struct platform_device *pdev;
+	struct msm_dp *dp_display;
 
 	pdev = to_platform_device(dev);
+	dp_display = platform_get_drvdata(pdev);
 	audio = dp_audio_get_data(pdev);
 	if (IS_ERR(audio)) {
 		DRM_ERROR("failed to get audio data\n");
 		return;
 	}
 
+	/*
+	 * if audio was not enabled there is no need
+	 * to execute the shutdown and we can bail out early.
+	 * This also makes sure that we dont cause an unclocked
+	 * access when audio subsystem calls this without DP being
+	 * connected. is_connected cannot be used here as its set
+	 * to false earlier than this call
+	 */
+	if (!dp_display->audio_enabled)
+		return;
+
 	dp_audio_enable(audio, false);
+	/* signal the dp display to safely shutdown clocks */
+	dp_display_signal_audio_complete(dp_display);
 }
 
 static const struct hdmi_codec_ops dp_audio_codec_ops = {
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 32d2236b20b2..6f7795dc9bc3 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -82,7 +82,6 @@ struct dp_display_private {
 
 	/* state variables */
 	bool core_initialized;
-	bool power_on;
 	bool hpd_irq_on;
 	bool audio_supported;
 
@@ -104,6 +103,9 @@ struct dp_display_private {
 	struct dp_display_mode dp_mode;
 	struct msm_dp dp_display;
 
+	/* wait for audio signaling */
+	struct completion audio_comp;
+
 	/* event related only access by event thread */
 	struct mutex event_mutex;
 	wait_queue_head_t event_q;
@@ -177,6 +179,15 @@ static int dp_del_event(struct dp_display_private *dp_priv, u32 event)
 	return 0;
 }
 
+void dp_display_signal_audio_complete(struct msm_dp *dp_display)
+{
+	struct dp_display_private *dp;
+
+	dp = container_of(dp_display, struct dp_display_private, dp_display);
+
+	complete_all(&dp->audio_comp);
+}
+
 static int dp_display_bind(struct device *dev, struct device *master,
 			   void *data)
 {
@@ -599,6 +610,7 @@ static int dp_hpd_unplug_handle(struct dp_display_private *dp, u32 data)
 
 	/* signal the disconnect event early to ensure proper teardown */
 	dp_display_handle_plugged_change(g_dp_display, false);
+	reinit_completion(&dp->audio_comp);
 
 	dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_PLUG_INT_MASK |
 					DP_DP_IRQ_HPD_INT_MASK, true);
@@ -793,15 +805,18 @@ static int dp_display_prepare(struct msm_dp *dp)
 static int dp_display_enable(struct dp_display_private *dp, u32 data)
 {
 	int rc = 0;
+	struct msm_dp *dp_display;
 
-	if (dp->power_on) {
+	dp_display = g_dp_display;
+
+	if (dp_display->power_on) {
 		DRM_DEBUG_DP("Link already setup, return\n");
 		return 0;
 	}
 
 	rc = dp_ctrl_on_stream(dp->ctrl);
 	if (!rc)
-		dp->power_on = true;
+		dp_display->power_on = true;
 
 	/* complete resume_comp regardless it is armed or not */
 	complete(&dp->resume_comp);
@@ -829,14 +844,27 @@ static int dp_display_post_enable(struct msm_dp *dp_display)
 
 static int dp_display_disable(struct dp_display_private *dp, u32 data)
 {
-	if (!dp->power_on)
+	struct msm_dp *dp_display;
+
+	dp_display = g_dp_display;
+
+	if (!dp_display->power_on)
 		return -EINVAL;
 
+	/* wait only if audio was enabled */
+	if (dp_display->audio_enabled) {
+		if (!wait_for_completion_timeout(&dp->audio_comp,
+				HZ * 5))
+			DRM_ERROR("audio comp timeout\n");
+	}
+
+	dp_display->audio_enabled = false;
+
 	dp_ctrl_off(dp->ctrl);
 
 	dp->core_initialized = false;
 
-	dp->power_on = false;
+	dp_display->power_on = false;
 
 	return 0;
 }
@@ -1152,6 +1180,8 @@ static int dp_display_probe(struct platform_device *pdev)
 	/* Store DP audio handle inside DP display */
 	g_dp_display->dp_audio = dp->audio;
 
+	init_completion(&dp->audio_comp);
+
 	platform_set_drvdata(pdev, g_dp_display);
 
 	rc = component_add(&pdev->dev, &dp_display_comp_ops);
diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
index 5020faf360db..8b78b40bbd6c 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.h
+++ b/drivers/gpu/drm/msm/dp/dp_display.h
@@ -15,6 +15,8 @@ struct msm_dp {
 	struct drm_connector *connector;
 	struct drm_encoder *encoder;
 	bool is_connected;
+	bool audio_enabled;
+	bool power_on;
 
 	hdmi_codec_plugged_cb plugged_cb;
 
@@ -32,6 +34,7 @@ int dp_display_get_modes(struct msm_dp *dp_display,
 int dp_display_request_irq(struct msm_dp *dp_display);
 bool dp_display_check_video_test(struct msm_dp *dp_display);
 int dp_display_get_test_bpp(struct msm_dp *dp_display);
+void dp_display_signal_audio_complete(struct msm_dp *dp_display);
 
 void __init msm_dp_pll_driver_register(void);
 void __exit msm_dp_pll_driver_unregister(void);