drm/nouveau: determine a value for display_info.bpc if edid doesn't
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c
index 5e830a5..fc42ea8 100644
--- a/drivers/gpu/drm/nouveau/nouveau_connector.c
+++ b/drivers/gpu/drm/nouveau/nouveau_connector.c
@@ -644,6 +644,46 @@
return modes;
}
+static void
+nouveau_connector_detect_depth(struct drm_connector *connector)
+{
+ struct drm_nouveau_private *dev_priv = connector->dev->dev_private;
+ struct nouveau_connector *nv_connector = nouveau_connector(connector);
+ struct nouveau_encoder *nv_encoder = nv_connector->detected_encoder;
+ struct nvbios *bios = &dev_priv->vbios;
+ struct drm_display_mode *mode = nv_connector->native_mode;
+ bool duallink;
+
+ /* if the edid is feeling nice enough to provide this info, use it */
+ if (nv_connector->edid && connector->display_info.bpc)
+ return;
+
+ /* if not, we're out of options unless we're LVDS, default to 6bpc */
+ connector->display_info.bpc = 6;
+ if (nv_encoder->dcb->type != OUTPUT_LVDS)
+ return;
+
+ /* LVDS: panel straps */
+ if (bios->fp_no_ddc) {
+ if (bios->fp.if_is_24bit)
+ connector->display_info.bpc = 8;
+ return;
+ }
+
+ /* LVDS: DDC panel, need to first determine the number of links to
+ * know which if_is_24bit flag to check...
+ */
+ if (nv_connector->edid &&
+ nv_connector->dcb->type == DCB_CONNECTOR_LVDS_SPWG)
+ duallink = ((u8 *)nv_connector->edid)[121] == 2;
+ else
+ duallink = mode->clock >= bios->fp.duallink_transition_clk;
+
+ if ((!duallink && (bios->fp.strapless_is_24bit & 1)) ||
+ ( duallink && (bios->fp.strapless_is_24bit & 2)))
+ connector->display_info.bpc = 8;
+}
+
static int
nouveau_connector_get_modes(struct drm_connector *connector)
{
@@ -688,6 +728,12 @@
ret = 1;
}
+ /* Attempt to determine display colour depth, this has to happen after
+ * we've determined the "native" mode for LVDS, as the VBIOS tables
+ * require us to compare against a pixel clock in some cases..
+ */
+ nouveau_connector_detect_depth(connector);
+
if (nv_encoder->dcb->type == OUTPUT_TV)
ret = get_slave_funcs(encoder)->get_modes(encoder, connector);