edid: Set timings flags according to edid

Timing flags are never set, so they may contain garbage. Since some
drivers check them, video output may be broken on those drivers.

Initialize them to 0 and check for few common flags.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Reviewed-by: Simon Glass <sjg@chromium.org>

common/edid.c

@@ -85,6 +85,7 @@ static void decode_timing(u8 *buf, struct display_timing *timing)
 	uint x_mm, y_mm;
 	unsigned int ha, hbl, hso, hspw, hborder;
 	unsigned int va, vbl, vso, vspw, vborder;
+	struct edid_detailed_timing *t = (struct edid_detailed_timing *)buf;
 
 	/* Edid contains pixel clock in terms of 10KHz */
 	set_entry(&timing->pixelclock, (buf[0] + (buf[1] << 8)) * 10000);
@@ -111,6 +112,19 @@ static void decode_timing(u8 *buf, struct display_timing *timing)
 	set_entry(&timing->vback_porch, vbl - vso - vspw);
 	set_entry(&timing->vsync_len, vspw);
 
+	timing->flags = 0;
+	if (EDID_DETAILED_TIMING_FLAG_HSYNC_POLARITY(*t))
+		timing->flags |= DISPLAY_FLAGS_HSYNC_HIGH;
+	else
+		timing->flags |= DISPLAY_FLAGS_HSYNC_LOW;
+	if (EDID_DETAILED_TIMING_FLAG_VSYNC_POLARITY(*t))
+		timing->flags |= DISPLAY_FLAGS_VSYNC_HIGH;
+	else
+		timing->flags |= DISPLAY_FLAGS_VSYNC_LOW;
+
+	if (EDID_DETAILED_TIMING_FLAG_INTERLACED(*t))
+		timing->flags = DISPLAY_FLAGS_INTERLACED;
+
 	debug("Detailed mode clock %u Hz, %d mm x %d mm\n"
 	      "               %04x %04x %04x %04x hborder %x\n"
 	      "               %04x %04x %04x %04x vborder %x\n",