EDID: Fix interlaced detailed timings to be frame size, not field size

Signed-off-by: Adam Jackson <ajax@redhat.com>

hw/xfree86/modes/xf86EdidModes.c

@@ -502,6 +502,45 @@ DDCModesFromStandardTiming(struct std_timings *timing, ddc_quirk_t quirks,
     return Modes;
 }
 
+static void
+DDCModeDoInterlaceQuirks(DisplayModePtr mode)
+{
+    /*
+     * EDID is delightfully ambiguous about how interlaced modes are to be
+     * encoded.  X's internal representation is of frame height, but some
+     * HDTV detailed timings are encoded as field height.
+     *
+     * The format list here is from CEA, in frame size.  Technically we
+     * should be checking refresh rate too.  Whatever.
+     */
+    static const struct {
+	int w, h;
+    } cea_interlaced[] = {
+	{ 1920, 1080 },
+	{  720,  480 },
+	{ 1440,  480 },
+	{ 2880,  480 },
+	{  720,  576 },
+	{ 1440,  576 },
+	{ 2880,  576 },
+    };
+    static const int n_modes = sizeof(cea_interlaced)/sizeof(cea_interlaced[0]);
+    int i;
+
+    for (i = 0; i < n_modes; i++) {
+	if ((mode->HDisplay == cea_interlaced[i].w) &&
+	    (mode->VDisplay == cea_interlaced[i].h / 2)) {
+	    mode->VDisplay *= 2;
+	    mode->VSyncStart *= 2;
+	    mode->VSyncEnd *= 2;
+	    mode->VTotal *= 2;
+	    mode->VTotal |= 1;
+	}
+    }
+
+    mode->Flags |= V_INTERLACE;
+}
+
 /*
  *
  */
@@ -569,7 +608,7 @@ DDCModeFromDetailedTiming(int scrnIndex, struct detailed_timings *timing,
     /* We ignore h/v_size and h/v_border for now. */
 
     if (timing->interlaced)
-        Mode->Flags |= V_INTERLACE;
+	DDCModeDoInterlaceQuirks(Mode);
 
     if (quirks & DDC_QUIRK_DETAILED_SYNC_PP)
 	Mode->Flags |= V_PVSYNC | V_PHSYNC;