drm/fbdev: fix cloning on fbcon
Simple cloning rules compared to server:
(a) single crtc
(b) > 1 connector active
(c) check command line mode
(d) try and find 1024x768 DMT mode if no command line.
(e) fail to clone
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index f7b8fca..b3779d2 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1070,6 +1070,79 @@
}
}
+static bool drm_target_cloned(struct drm_fb_helper *fb_helper,
+ struct drm_display_mode **modes,
+ bool *enabled, int width, int height)
+{
+ int count, i, j;
+ bool can_clone = false;
+ struct drm_fb_helper_connector *fb_helper_conn;
+ struct drm_display_mode *dmt_mode, *mode;
+
+ /* only contemplate cloning in the single crtc case */
+ if (fb_helper->crtc_count > 1)
+ return false;
+
+ count = 0;
+ for (i = 0; i < fb_helper->connector_count; i++) {
+ if (enabled[i])
+ count++;
+ }
+
+ /* only contemplate cloning if more than one connector is enabled */
+ if (count <= 1)
+ return false;
+
+ /* check the command line or if nothing common pick 1024x768 */
+ can_clone = true;
+ for (i = 0; i < fb_helper->connector_count; i++) {
+ if (!enabled[i])
+ continue;
+ fb_helper_conn = fb_helper->connector_info[i];
+ modes[i] = drm_pick_cmdline_mode(fb_helper_conn, width, height);
+ if (!modes[i]) {
+ can_clone = false;
+ break;
+ }
+ for (j = 0; j < i; j++) {
+ if (!enabled[j])
+ continue;
+ if (!drm_mode_equal(modes[j], modes[i]))
+ can_clone = false;
+ }
+ }
+
+ if (can_clone) {
+ DRM_DEBUG_KMS("can clone using command line\n");
+ return true;
+ }
+
+ /* try and find a 1024x768 mode on each connector */
+ can_clone = true;
+ dmt_mode = drm_mode_find_dmt(fb_helper->dev, 1024, 768, 60);
+
+ for (i = 0; i < fb_helper->connector_count; i++) {
+
+ if (!enabled[i])
+ continue;
+
+ fb_helper_conn = fb_helper->connector_info[i];
+ list_for_each_entry(mode, &fb_helper_conn->connector->modes, head) {
+ if (drm_mode_equal(mode, dmt_mode))
+ modes[i] = mode;
+ }
+ if (!modes[i])
+ can_clone = false;
+ }
+
+ if (can_clone) {
+ DRM_DEBUG_KMS("can clone using 1024x768\n");
+ return true;
+ }
+ DRM_INFO("kms: can't enable cloning when we probably wanted to.\n");
+ return false;
+}
+
static bool drm_target_preferred(struct drm_fb_helper *fb_helper,
struct drm_display_mode **modes,
bool *enabled, int width, int height)
@@ -1163,8 +1236,12 @@
break;
if (o < n) {
- /* ignore cloning for now */
- continue;
+ /* ignore cloning unless only a single crtc */
+ if (fb_helper->crtc_count > 1)
+ continue;
+
+ if (!drm_mode_equal(modes[o], modes[n]))
+ continue;
}
crtcs[n] = crtc;
@@ -1214,9 +1291,12 @@
drm_enable_connectors(fb_helper, enabled);
- ret = drm_target_preferred(fb_helper, modes, enabled, width, height);
- if (!ret)
- DRM_ERROR("Unable to find initial modes\n");
+ ret = drm_target_cloned(fb_helper, modes, enabled, width, height);
+ if (!ret) {
+ ret = drm_target_preferred(fb_helper, modes, enabled, width, height);
+ if (!ret)
+ DRM_ERROR("Unable to find initial modes\n");
+ }
DRM_DEBUG_KMS("picking CRTCs for %dx%d config\n", width, height);