drm/exynos: let drm handle edid allocations

There's no need to allocate edid twice and do a memcpy when drm helpers
exist to do just that. This patch cleans that interaction up, and
doesn't keep the edid hanging around in the connector.

v4:
- removed error check for drm_mode_connector_update_edid_property
which is expected to fail for Virtual Connectors like VIDI.
Thanks to Seung-Woo Kim.

v3:
- removed MAX_EDID as it is not used anymore.

v2:
- changed vidi_get_edid callback inside vidi driver.
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_connector.c

@@ -18,7 +18,6 @@
 #include "exynos_drm_drv.h"
 #include "exynos_drm_encoder.h"
 
-#define MAX_EDID 256
 #define to_exynos_connector(x)	container_of(x, struct exynos_drm_connector,\
 				drm_connector)
 
@@ -96,7 +95,9 @@ static int exynos_drm_connector_get_modes(struct drm_connector *connector)
 					to_exynos_connector(connector);
 	struct exynos_drm_manager *manager = exynos_connector->manager;
 	struct exynos_drm_display_ops *display_ops = manager->display_ops;
-	unsigned int count;
+	struct edid *edid = NULL;
+	unsigned int count = 0;
+	int ret;
 
 	DRM_DEBUG_KMS("%s\n", __FILE__);
 
@@ -114,27 +115,21 @@ static int exynos_drm_connector_get_modes(struct drm_connector *connector)
 	 * because lcd panel has only one mode.
 	 */
 	if (display_ops->get_edid) {
-		int ret;
-		void *edid;
-
-		edid = kzalloc(MAX_EDID, GFP_KERNEL);
-		if (!edid) {
-			DRM_ERROR("failed to allocate edid\n");
-			return 0;
+		edid = display_ops->get_edid(manager->dev, connector);
+		if (IS_ERR_OR_NULL(edid)) {
+			ret = PTR_ERR(edid);
+			edid = NULL;
+			DRM_ERROR("Panel operation get_edid failed %d\n", ret);
+			goto out;
 		}
 
-		ret = display_ops->get_edid(manager->dev, connector,
-						edid, MAX_EDID);
-		if (ret < 0) {
-			DRM_ERROR("failed to get edid data.\n");
-			kfree(edid);
-			edid = NULL;
-			return 0;
+		count = drm_add_edid_modes(connector, edid);
+		if (count < 0) {
+			DRM_ERROR("Add edid modes failed %d\n", count);
+			goto out;
 		}
 
 		drm_mode_connector_update_edid_property(connector, edid);
-		count = drm_add_edid_modes(connector, edid);
-		kfree(edid);
 	} else {
 		struct exynos_drm_panel_info *panel;
 		struct drm_display_mode *mode = drm_mode_create(connector->dev);
@@ -161,6 +156,8 @@ static int exynos_drm_connector_get_modes(struct drm_connector *connector)
 		count = 1;
 	}
 
+out:
+	kfree(edid);
 	return count;
 }
 

drivers/gpu/drm/exynos/exynos_drm_drv.h

@@ -148,8 +148,8 @@ struct exynos_drm_overlay {
 struct exynos_drm_display_ops {
 	enum exynos_drm_output_type type;
 	bool (*is_connected)(struct device *dev);
-	int (*get_edid)(struct device *dev, struct drm_connector *connector,
-				u8 *edid, int len);
+	struct edid *(*get_edid)(struct device *dev,
+			struct drm_connector *connector);
 	void *(*get_panel)(struct device *dev);
 	int (*check_timing)(struct device *dev, void *timing);
 	int (*power_on)(struct device *dev, int mode);

drivers/gpu/drm/exynos/exynos_drm_hdmi.c

@@ -108,18 +108,17 @@ static bool drm_hdmi_is_connected(struct device *dev)
 	return false;
 }
 
-static int drm_hdmi_get_edid(struct device *dev,
-		struct drm_connector *connector, u8 *edid, int len)
+struct edid *drm_hdmi_get_edid(struct device *dev,
+			struct drm_connector *connector)
 {
 	struct drm_hdmi_context *ctx = to_context(dev);
 
 	DRM_DEBUG_KMS("%s\n", __FILE__);
 
 	if (hdmi_ops && hdmi_ops->get_edid)
-		return hdmi_ops->get_edid(ctx->hdmi_ctx->ctx, connector, edid,
-					  len);
+		return hdmi_ops->get_edid(ctx->hdmi_ctx->ctx, connector);
 
-	return 0;
+	return NULL;
 }
 
 static int drm_hdmi_check_timing(struct device *dev, void *timing)

drivers/gpu/drm/exynos/exynos_drm_hdmi.h

@@ -30,8 +30,8 @@ struct exynos_drm_hdmi_context {
 struct exynos_hdmi_ops {
 	/* display */
 	bool (*is_connected)(void *ctx);
-	int (*get_edid)(void *ctx, struct drm_connector *connector,
-			u8 *edid, int len);
+	struct edid *(*get_edid)(void *ctx,
+			struct drm_connector *connector);
 	int (*check_timing)(void *ctx, void *timing);
 	int (*power_on)(void *ctx, int mode);
 

drivers/gpu/drm/exynos/exynos_drm_vidi.c

@@ -98,10 +98,12 @@ static bool vidi_display_is_connected(struct device *dev)
 	return ctx->connected ? true : false;
 }
 
-static int vidi_get_edid(struct device *dev, struct drm_connector *connector,
-				u8 *edid, int len)
+static struct edid *vidi_get_edid(struct device *dev,
+			struct drm_connector *connector)
 {
 	struct vidi_context *ctx = get_vidi_context(dev);
+	struct edid *edid;
+	int edid_len;
 
 	DRM_DEBUG_KMS("%s\n", __FILE__);
 
@@ -111,13 +113,18 @@ static int vidi_get_edid(struct device *dev, struct drm_connector *connector,
 	 */
 	if (!ctx->raw_edid) {
 		DRM_DEBUG_KMS("raw_edid is null.\n");
-		return -EFAULT;
+		return ERR_PTR(-EFAULT);
 	}
 
-	memcpy(edid, ctx->raw_edid, min((1 + ctx->raw_edid->extensions)
-					* EDID_LENGTH, len));
+	edid_len = (1 + ctx->raw_edid->extensions) * EDID_LENGTH;
+	edid = kzalloc(edid_len, GFP_KERNEL);
+	if (!edid) {
+		DRM_DEBUG_KMS("failed to allocate edid\n");
+		return ERR_PTR(-ENOMEM);
+	}
 
-	return 0;
+	memcpy(edid, ctx->raw_edid, edid_len);
+	return edid;
 }
 
 static void *vidi_get_panel(struct device *dev)

drivers/gpu/drm/exynos/exynos_hdmi.c

@@ -1391,8 +1391,7 @@ static bool hdmi_is_connected(void *ctx)
 	return hdata->hpd;
 }
 
-static int hdmi_get_edid(void *ctx, struct drm_connector *connector,
-				u8 *edid, int len)
+static struct edid *hdmi_get_edid(void *ctx, struct drm_connector *connector)
 {
 	struct edid *raw_edid;
 	struct hdmi_context *hdata = ctx;
@@ -1400,22 +1399,18 @@ static int hdmi_get_edid(void *ctx, struct drm_connector *connector,
 	DRM_DEBUG_KMS("[%d] %s\n", __LINE__, __func__);
 
 	if (!hdata->ddc_port)
-		return -ENODEV;
+		return ERR_PTR(-ENODEV);
 
 	raw_edid = drm_get_edid(connector, hdata->ddc_port->adapter);
-	if (raw_edid) {
+	if (!raw_edid)
+		return ERR_PTR(-ENODEV);
+
 	hdata->dvi_mode = !drm_detect_hdmi_monitor(raw_edid);
-		memcpy(edid, raw_edid, min((1 + raw_edid->extensions)
-					* EDID_LENGTH, len));
 	DRM_DEBUG_KMS("%s : width[%d] x height[%d]\n",
 		(hdata->dvi_mode ? "dvi monitor" : "hdmi monitor"),
 		raw_edid->width_cm, raw_edid->height_cm);
-		kfree(raw_edid);
-	} else {
-		return -ENODEV;
-	}
 
-	return 0;
+	return raw_edid;
 }
 
 static int hdmi_v13_check_timing(struct fb_videomode *check_timing)