1 files changed, 20 insertions, 19 deletions

diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c
index adbd5a367395..da46a433bf74 100644
--- a/drivers/gpu/drm/msm/dp/dp_aux.c
+++ b/drivers/gpu/drm/msm/dp/dp_aux.c
@@ -38,6 +38,7 @@ struct dp_aux_private {
 	bool no_send_stop;
 	bool initted;
 	bool is_edp;
+	bool enable_xfers;
 	u32 offset;
 	u32 segment;
 
@@ -87,8 +88,7 @@ static ssize_t dp_aux_write(struct dp_aux_private *aux,
 		/* index = 0, write */
 		if (i == 0)
 			reg |= DP_AUX_DATA_INDEX_WRITE;
-		aux->catalog->aux_data = reg;
-		dp_catalog_aux_write_data(aux->catalog);
+		dp_catalog_aux_write_data(aux->catalog, reg);
 	}
 
 	dp_catalog_aux_clear_trans(aux->catalog, false);
@@ -106,8 +106,7 @@ static ssize_t dp_aux_write(struct dp_aux_private *aux,
 	}
 
 	reg |= DP_AUX_TRANS_CTRL_GO;
-	aux->catalog->aux_data = reg;
-	dp_catalog_aux_write_trans(aux->catalog);
+	dp_catalog_aux_write_trans(aux->catalog, reg);
 
 	return len;
 }
@@ -145,8 +144,7 @@ static ssize_t dp_aux_cmd_fifo_rx(struct dp_aux_private *aux,
 	data = DP_AUX_DATA_INDEX_WRITE; /* INDEX_WRITE */
 	data |= DP_AUX_DATA_READ;  /* read */
 
-	aux->catalog->aux_data = data;
-	dp_catalog_aux_write_data(aux->catalog);
+	dp_catalog_aux_write_data(aux->catalog, data);
 
 	dp = msg->buffer;
 
@@ -305,19 +303,14 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux,
 	}
 
 	/*
-	 * For eDP it's important to give a reasonably long wait here for HPD
-	 * to be asserted. This is because the panel driver may have _just_
-	 * turned on the panel and then tried to do an AUX transfer. The panel
-	 * driver has no way of knowing when the panel is ready, so it's up
-	 * to us to wait. For DP we never get into this situation so let's
-	 * avoid ever doing the extra long wait for DP.
+	 * If we're using DP and an external display isn't connected then the
+	 * transfer won't succeed. Return right away. If we don't do this we
+	 * can end up with long timeouts if someone tries to access the DP AUX
+	 * character device when no DP device is connected.
 	 */
-	if (aux->is_edp) {
-		ret = dp_catalog_aux_wait_for_hpd_connect_state(aux->catalog);
-		if (ret) {
-			DRM_DEBUG_DP("Panel not ready for aux transactions\n");
-			goto exit;
-		}
+	if (!aux->is_edp && !aux->enable_xfers) {
+		ret = -ENXIO;
+		goto exit;
 	}
 
 	dp_aux_update_offset_and_segment(aux, msg);
@@ -436,6 +429,14 @@ irqreturn_t dp_aux_isr(struct drm_dp_aux *dp_aux)
 	return IRQ_HANDLED;
 }
 
+void dp_aux_enable_xfers(struct drm_dp_aux *dp_aux, bool enabled)
+{
+	struct dp_aux_private *aux;
+
+	aux = container_of(dp_aux, struct dp_aux_private, dp_aux);
+	aux->enable_xfers = enabled;
+}
+
 void dp_aux_reconfig(struct drm_dp_aux *dp_aux)
 {
 	struct dp_aux_private *aux;
@@ -513,7 +514,7 @@ static int dp_wait_hpd_asserted(struct drm_dp_aux *dp_aux,
 	aux = container_of(dp_aux, struct dp_aux_private, dp_aux);
 
 	pm_runtime_get_sync(aux->dev);
-	ret = dp_catalog_aux_wait_for_hpd_connect_state(aux->catalog);
+	ret = dp_catalog_aux_wait_for_hpd_connect_state(aux->catalog, wait_us);
 	pm_runtime_put_sync(aux->dev);
 
 	return ret;