drm/tegra: Track HDMI enable state

The DRM core doesn't track enable and disable state of encoders and/or
connectors, so calls to the output's .enable() and .disable() are not
guaranteed to be balanced. Track the enable state internally so that
calls to regulator and clock frameworks remain balanced.

Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/gpu/drm/tegra/hdmi.c b/drivers/gpu/drm/tegra/hdmi.c
index d8cc81f5de38..19ce750e4856 100644
--- a/drivers/gpu/drm/tegra/hdmi.c
+++ b/drivers/gpu/drm/tegra/hdmi.c
@@ -40,6 +40,7 @@ struct tegra_hdmi {
         struct host1x_client client;
         struct tegra_output output;
         struct device *dev;
+        bool enabled;
 
         struct regulator *vdd;
         struct regulator *pll;
@@ -699,6 +700,9 @@ static int tegra_output_hdmi_enable(struct tegra_output *output)
         int retries = 1000;
         int err;
 
+        if (hdmi->enabled)
+                return 0;
+
         hdmi->dvi = !tegra_output_is_hdmi(output);
 
         pclk = mode->clock * 1000;
@@ -906,6 +910,8 @@ static int tegra_output_hdmi_enable(struct tegra_output *output)
 
         /* TODO: add HDCP support */
 
+        hdmi->enabled = true;
+
         return 0;
 }
 
@@ -913,10 +919,15 @@ static int tegra_output_hdmi_disable(struct tegra_output *output)
 {
         struct tegra_hdmi *hdmi = to_hdmi(output);
 
+        if (!hdmi->enabled)
+                return 0;
+
         reset_control_assert(hdmi->rst);
         clk_disable(hdmi->clk);
         regulator_disable(hdmi->pll);
 
+        hdmi->enabled = false;
+
         return 0;
 }