drm/omap: Remove connection checks from display .enable() and .remove()

The displays (connectors, panels and encoders) return an error from
their .enable() handler when the dss device is not connected. They also
disconnect the dss device explicitly from their .remove() handler if it
is still connected.

Those safety checks are not needed:

- The .enable() handler is called from code paths that access the dss
  devices chain from the display device, which is set to NULL when the
  device isn't connected.

- The .remove() handler can only be called when unloading the module as
  the driver has the suppress_bind_attrs attribute set, and a reference
  to the module is taken when constructing the dss devices chain, so the
  module can only be unloaded when the dss device is disconnected.

Remove the safety checks.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

6 files changed, 10 insertions, 35 deletions

diff --git a/drivers/gpu/drm/omapdrm/displays/encoder-opa362.c b/drivers/gpu/drm/omapdrm/displays/encoder-opa362.c
index 4fefd80f53bb..0b1032625e42 100644
--- a/drivers/gpu/drm/omapdrm/displays/encoder-opa362.c
+++ b/drivers/gpu/drm/omapdrm/displays/encoder-opa362.c
@@ -49,9 +49,6 @@ static int opa362_enable(struct omap_dss_device *dssdev)
 
 	dev_dbg(dssdev->dev, "enable\n");
 
-	if (!omapdss_device_is_connected(dssdev))
-		return -ENODEV;
-
 	if (omapdss_device_is_enabled(dssdev))
 		return 0;
 
@@ -145,10 +142,6 @@ static int __exit opa362_remove(struct platform_device *pdev)
 	if (omapdss_device_is_enabled(dssdev))
 		opa362_disable(dssdev);
 
-	WARN_ON(omapdss_device_is_connected(dssdev));
-	if (omapdss_device_is_connected(dssdev))
-		omapdss_device_disconnect(NULL, dssdev);
-
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/omapdrm/displays/encoder-tfp410.c b/drivers/gpu/drm/omapdrm/displays/encoder-tfp410.c
index f1a748353279..fcc2dc5188a2 100644
--- a/drivers/gpu/drm/omapdrm/displays/encoder-tfp410.c
+++ b/drivers/gpu/drm/omapdrm/displays/encoder-tfp410.c
@@ -42,9 +42,6 @@ static int tfp410_enable(struct omap_dss_device *dssdev)
 	struct omap_dss_device *src = dssdev->src;
 	int r;
 
-	if (!omapdss_device_is_connected(dssdev))
-		return -ENODEV;
-
 	if (omapdss_device_is_enabled(dssdev))
 		return 0;
 
@@ -139,10 +136,6 @@ static int __exit tfp410_remove(struct platform_device *pdev)
 	if (omapdss_device_is_enabled(dssdev))
 		tfp410_disable(dssdev);
 
-	WARN_ON(omapdss_device_is_connected(dssdev));
-	if (omapdss_device_is_connected(dssdev))
-		omapdss_device_disconnect(NULL, dssdev);
-
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/omapdrm/displays/encoder-tpd12s015.c b/drivers/gpu/drm/omapdrm/displays/encoder-tpd12s015.c
index 94de55fd8884..1a2bc59bf104 100644
--- a/drivers/gpu/drm/omapdrm/displays/encoder-tpd12s015.c
+++ b/drivers/gpu/drm/omapdrm/displays/encoder-tpd12s015.c
@@ -229,10 +229,6 @@ static int __exit tpd_remove(struct platform_device *pdev)
 	if (omapdss_device_is_enabled(dssdev))
 		tpd_disable(dssdev);
 
-	WARN_ON(omapdss_device_is_connected(dssdev));
-	if (omapdss_device_is_connected(dssdev))
-		omapdss_device_disconnect(NULL, dssdev);
-
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/omapdrm/dss/base.c b/drivers/gpu/drm/omapdrm/dss/base.c
index 472f56e3de70..787157b00694 100644
--- a/drivers/gpu/drm/omapdrm/dss/base.c
+++ b/drivers/gpu/drm/omapdrm/dss/base.c
@@ -185,6 +185,11 @@ done:
 }
 EXPORT_SYMBOL(omapdss_device_get_next);
 
+static bool omapdss_device_is_connected(struct omap_dss_device *dssdev)
+{
+	return dssdev->src;
+}
+
 int omapdss_device_connect(struct dss_device *dss,
 			   struct omap_dss_device *src,
 			   struct omap_dss_device *dst)
diff --git a/drivers/gpu/drm/omapdrm/dss/omapdss.h b/drivers/gpu/drm/omapdrm/dss/omapdss.h
index de0520a8eb4e..698155dd7941 100644
--- a/drivers/gpu/drm/omapdrm/dss/omapdss.h
+++ b/drivers/gpu/drm/omapdrm/dss/omapdss.h
@@ -505,11 +505,6 @@ int omap_dispc_unregister_isr(omap_dispc_isr_t isr, void *arg, u32 mask);
 int omapdss_compat_init(void);
 void omapdss_compat_uninit(void);
 
-static inline bool omapdss_device_is_connected(struct omap_dss_device *dssdev)
-{
-	return dssdev->src;
-}
-
 static inline bool omapdss_device_is_enabled(struct omap_dss_device *dssdev)
 {
 	return dssdev->state == OMAP_DSS_DISPLAY_ACTIVE;
diff --git a/drivers/gpu/drm/omapdrm/omap_encoder.c b/drivers/gpu/drm/omapdrm/omap_encoder.c
index 5427c0b3ff9e..3c3d88e1df38 100644
--- a/drivers/gpu/drm/omapdrm/omap_encoder.c
+++ b/drivers/gpu/drm/omapdrm/omap_encoder.c
@@ -168,24 +168,17 @@ static void omap_encoder_enable(struct drm_encoder *encoder)
 
 	dev_dbg(dev->dev, "enable(%s)\n", dssdev->name);
 
-	if (!omapdss_device_is_connected(dssdev)) {
-		r = -ENODEV;
-		goto error;
-	}
-
 	if (omapdss_device_is_enabled(dssdev))
 		return;
 
 	r = dssdev->ops->enable(dssdev);
-	if (r)
-		goto error;
+	if (r) {
+		dev_err(dev->dev, "Failed to enable display '%s': %d\n",
+			dssdev->name, r);
+		return;
+	}
 
 	dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
-	return;
-
-error:
-	dev_err(dev->dev, "Failed to enable display '%s': %d\n",
-		dssdev->name, r);
 }
 
 static int omap_encoder_atomic_check(struct drm_encoder *encoder,