drm/edid: Remove arbitrary EDID extension limit

Signed-off-by: NAdam Jackson <ajax@redhat.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_crtc.c

@@ -33,6 +33,7 @@
 #include "drm.h"
 #include "drmP.h"
 #include "drm_crtc.h"
+#include "drm_edid.h"
 
 struct drm_prop_enum_list {
 	int type;
@@ -2349,7 +2350,7 @@ int drm_mode_connector_update_edid_property(struct drm_connector *connector,
 					    struct edid *edid)
 {
 	struct drm_device *dev = connector->dev;
-	int ret = 0;
+	int ret = 0, size;
 
 	if (connector->edid_blob_ptr)
 		drm_property_destroy_blob(dev, connector->edid_blob_ptr);
@@ -2361,7 +2362,9 @@ int drm_mode_connector_update_edid_property(struct drm_connector *connector,
 		return ret;
 	}
 
-	connector->edid_blob_ptr = drm_property_create_blob(connector->dev, 128, edid);
+	size = EDID_LENGTH * (1 + edid->extensions);
+	connector->edid_blob_ptr = drm_property_create_blob(connector->dev,
+							    size, edid);
 
 	ret = drm_connector_property_set_value(connector,
 					       dev->mode_config.edid_property,

drivers/gpu/drm/drm_edid.c

@@ -1325,7 +1325,6 @@ static int add_detailed_info_eedid(struct drm_connector *connector,
 	int i, modes = 0;
 	char *edid_ext = NULL;
 	struct detailed_timing *timing;
-	int edid_ext_num;
 	int start_offset, end_offset;
 	int timing_level;
 
@@ -1342,19 +1341,15 @@ static int add_detailed_info_eedid(struct drm_connector *connector,
 		return 0;
 	}
 
-	/* Chose real EDID extension number */
-	edid_ext_num = edid->extensions > DRM_MAX_EDID_EXT_NUM ?
-		DRM_MAX_EDID_EXT_NUM : edid->extensions;
-
 	/* Find CEA extension */
-	for (i = 0; i < edid_ext_num; i++) {
+	for (i = 0; i < edid->extensions; i++) {
 		edid_ext = (char *)edid + EDID_LENGTH * (i + 1);
 		/* This block is CEA extension */
 		if (edid_ext[0] == 0x02)
 			break;
 	}
 
-	if (i == edid_ext_num) {
+	if (i == edid->extensions) {
 		/* if there is no additional timing EDID block, return */
 		return 0;
 	}
@@ -1393,7 +1388,7 @@ static int add_detailed_info_eedid(struct drm_connector *connector,
 bool drm_detect_hdmi_monitor(struct edid *edid)
 {
 	char *edid_ext = NULL;
-	int i, hdmi_id, edid_ext_num;
+	int i, hdmi_id;
 	int start_offset, end_offset;
 	bool is_hdmi = false;
 
@@ -1401,19 +1396,15 @@ bool drm_detect_hdmi_monitor(struct edid *edid)
 	if (edid == NULL || edid->extensions == 0)
 		goto end;
 
-	/* Chose real EDID extension number */
-	edid_ext_num = edid->extensions > DRM_MAX_EDID_EXT_NUM ?
-		       DRM_MAX_EDID_EXT_NUM : edid->extensions;
-
 	/* Find CEA extension */
-	for (i = 0; i < edid_ext_num; i++) {
+	for (i = 0; i < edid->extensions; i++) {
 		edid_ext = (char *)edid + EDID_LENGTH * (i + 1);
 		/* This block is CEA extension */
 		if (edid_ext[0] == 0x02)
 			break;
 	}
 
-	if (i == edid_ext_num)
+	if (i == edid->extensions)
 		goto end;
 
 	/* Data block offset in CEA extension block */

drivers/gpu/drm/drm_sysfs.c

@@ -332,7 +332,7 @@ static struct device_attribute connector_attrs_opt1[] = {
 static struct bin_attribute edid_attr = {
 	.attr.name = "edid",
 	.attr.mode = 0444,
-	.size = 128,
+	.size = 0,
 	.read = edid_show,
 };
 

drivers/gpu/drm/radeon/radeon_combios.c

@@ -450,17 +450,17 @@ bool radeon_combios_check_hardcoded_edid(struct radeon_device *rdev)
 {
 	int edid_info;
 	struct edid *edid;
+	unsigned char *raw;
 	edid_info = combios_get_table_offset(rdev->ddev, COMBIOS_HARDCODED_EDID_TABLE);
 	if (!edid_info)
 		return false;
 
-	edid = kmalloc(EDID_LENGTH * (DRM_MAX_EDID_EXT_NUM + 1),
-		       GFP_KERNEL);
+	raw = rdev->bios + edid_info;
+	edid = kmalloc(EDID_LENGTH * (raw[0x7e] + 1), GFP_KERNEL);
 	if (edid == NULL)
 		return false;
 
-	memcpy((unsigned char *)edid,
-	       (unsigned char *)(rdev->bios + edid_info), EDID_LENGTH);
+	memcpy((unsigned char *)edid, raw, EDID_LENGTH * (raw[0x7e] + 1));
 
 	if (!drm_edid_is_valid(edid)) {
 		kfree(edid);

include/drm/drm_edid.h

@@ -201,7 +201,4 @@ struct edid {
 
 #define EDID_PRODUCT_ID(e) ((e)->prod_code[0] | ((e)->prod_code[1] << 8))
 
-/* define the number of Extension EDID block */
-#define DRM_MAX_EDID_EXT_NUM 4
-
 #endif /* __DRM_EDID_H__ */