xfree86: add drm modes on non-GTF panels

EDID1.4 replaced GTF Bit with Continuous or Non-Continuous Frequency Display.

Check the "Display Range Limits Descriptor" for GTF support.
If panel doesn't support GTF, then add gtf modes.

Otherwise X will only show the modes in "Detailed Timing Descriptor".

V2: Coding style changes.
V3: Coding style changes, remove unused variate.
V4: remove unused variate.

BugLink: https://gitlab.freedesktop.org/drm/intel/issues/313
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>

hw/xfree86/ddc/edid.h

@@ -262,6 +262,10 @@
 #define MAX_H (_MAX_H(c) + _MAX_H_OFFSET(c))
 #define _MAX_CLOCK(x) x[9]
 #define MAX_CLOCK _MAX_CLOCK(c)
+#define _DEFAULT_GTF(x) (x[10] == 0x00)
+#define DEFAULT_GTF _DEFAULT_GTF(c)
+#define _RANGE_LIMITS_ONLY(x) (x[10] == 0x01)
+#define RANGE_LIMITS_ONLY _RANGE_LIMITS_ONLY(c)
 #define _HAVE_2ND_GTF(x) (x[10] == 0x02)
 #define HAVE_2ND_GTF _HAVE_2ND_GTF(c)
 #define _F_2ND_GTF(x) (x[12] * 2)
@@ -477,6 +481,16 @@ struct detailed_timings {
 #define DS_VENDOR 0x101
 #define DS_VENDOR_MAX 0x110
 
+/*
+ * Display range limit Descriptor of EDID version1, reversion 4
+ */
+typedef enum {
+	DR_DEFAULT_GTF,
+	DR_LIMITS_ONLY,
+	DR_SECONDARY_GTF,
+	DR_CVT_SUPPORTED = 4,
+} DR_timing_flags;
+
 struct monitor_ranges {
     int min_v;
     int max_v;
@@ -495,6 +509,7 @@ struct monitor_ranges {
     char supported_blanking;
     char supported_scaling;
     int preferred_refresh;      /* in hz */
+    DR_timing_flags display_range_timing_flags;
 };
 
 struct whitePoints {
@@ -524,7 +539,7 @@ struct detailed_monitor_section {
         Uchar serial[13];
         Uchar ascii_data[13];
         Uchar name[13];
-        struct monitor_ranges ranges;   /* 56 */
+        struct monitor_ranges ranges;   /* 60 */
         struct std_timings std_t[5];    /* 80 */
         struct whitePoints wp[2];       /* 32 */
         /* color management data */

hw/xfree86/ddc/interpret_edid.c

@@ -672,6 +672,9 @@ get_monitor_ranges(Uchar * c, struct monitor_ranges *r)
     r->max_clock = 0;
     if (MAX_CLOCK != 0xff)      /* is specified? */
         r->max_clock = MAX_CLOCK * 10 + 5;
+
+    r->display_range_timing_flags = c[10];
+
     if (HAVE_2ND_GTF) {
         r->gtf_2nd_f = F_2ND_GTF;
         r->gtf_2nd_c = C_2ND_GTF;
@@ -751,6 +754,30 @@ validate_version(int scrnIndex, struct edid_version *r)
     return TRUE;
 }
 
+Bool
+gtf_supported(xf86MonPtr mon)
+{
+    int i;
+
+    if (!mon)
+        return FALSE;
+
+    if ((mon->ver.version == 1) && (mon->ver.revision < 4)) {
+        if (mon->features.msc & 0x1)
+	    return TRUE;
+    } else {
+        for (i = 0; i < DET_TIMINGS; i++) {
+            struct detailed_monitor_section *det_timing_des = &(mon->det_mon[i]);
+            if (det_timing_des && (det_timing_des->type == DS_RANGES) &&
+                (det_timing_des->section.ranges.display_range_timing_flags == DR_DEFAULT_GTF
+		|| det_timing_des->section.ranges.display_range_timing_flags == DR_SECONDARY_GTF))
+		    return TRUE;
+	}
+    }
+
+    return FALSE;
+}
+
 /*
  * Returns true if HDMI, false if definitely not or unknown.
  */

hw/xfree86/ddc/xf86DDC.h

@@ -48,6 +48,9 @@ extern _X_EXPORT Bool xf86SetDDCproperties(ScrnInfoPtr pScreen, xf86MonPtr DDC);
 extern _X_EXPORT Bool
  xf86MonitorIsHDMI(xf86MonPtr mon);
 
+extern _X_EXPORT Bool
+gtf_supported(xf86MonPtr mon);
+
 extern _X_EXPORT DisplayModePtr
 FindDMTMode(int hsize, int vsize, int refresh, Bool rb);
 

hw/xfree86/drivers/modesetting/drmmode_display.c

@@ -2459,7 +2459,7 @@ drmmode_output_add_gtf_modes(xf86OutputPtr output, DisplayModePtr Modes)
     int max_x = 0, max_y = 0;
     float max_vrefresh = 0.0;
 
-    if (mon && GTF_SUPPORTED(mon->features.msc))
+    if (mon && gtf_supported(mon))
         return Modes;
 
     if (!has_panel_fitter(output))

hw/xfree86/modes/xf86Crtc.c

@@ -1731,11 +1731,10 @@ xf86ProbeOutputModes(ScrnInfoPtr scrn, int maxX, int maxY)
 
         if (edid_monitor) {
             struct det_monrec_parameter p;
-            struct disp_features *features = &edid_monitor->features;
             struct cea_data_block *hdmi_db;
 
             /* if display is not continuous-frequency, don't add default modes */
-            if (!GTF_SUPPORTED(features->msc))
+            if (!gtf_supported(edid_monitor))
                 add_default_modes = FALSE;
 
             p.mon_rec = &mon_rec;