summaryrefslogtreecommitdiff
path: root/hw/xfree86/modes/xf86Modes.c
blob: 5b52bd76c291fda1e2303fc6c42db684ae72a8f4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
/* -*- c-basic-offset: 4 -*- */
/* $XdotOrg: xserver/xorg/hw/xfree86/common/xf86Mode.c,v 1.10 2006/03/07 16:00:57 libv Exp $ */
/* $XFree86: xc/programs/Xserver/hw/xfree86/common/xf86Mode.c,v 1.69 2003/10/08 14:58:28 dawes Exp $ */
/*
 * Copyright (c) 1997-2003 by The XFree86 Project, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Except as contained in this notice, the name of the copyright holder(s)
 * and author(s) shall not be used in advertising or otherwise to promote
 * the sale, use or other dealings in this Software without prior written
 * authorization from the copyright holder(s) and author(s).
 */

#ifdef HAVE_XORG_CONFIG_H
#include <xorg-config.h>
#else
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#endif

#include "xf86Modes.h"
#include "xf86Priv.h"

extern XF86ConfigPtr xf86configptr;

/**
 * @file this file contains symbols from xf86Mode.c and friends that are static
 * there but we still want to use.  We need to come up with better API here.
 */

#if XORG_VERSION_CURRENT <= XORG_VERSION_NUMERIC(7,2,99,2,0)
/**
 * Calculates the horizontal sync rate of a mode.
 *
 * Exact copy of xf86Mode.c's.
 */
double
xf86ModeHSync(DisplayModePtr mode)
{
    double hsync = 0.0;
    
    if (mode->HSync > 0.0)
	    hsync = mode->HSync;
    else if (mode->HTotal > 0)
	    hsync = (float)mode->Clock / (float)mode->HTotal;

    return hsync;
}

/**
 * Calculates the vertical refresh rate of a mode.
 *
 * Exact copy of xf86Mode.c's.
 */
double
xf86ModeVRefresh(DisplayModePtr mode)
{
    double refresh = 0.0;

    if (mode->VRefresh > 0.0)
	refresh = mode->VRefresh;
    else if (mode->HTotal > 0 && mode->VTotal > 0) {
	refresh = mode->Clock * 1000.0 / mode->HTotal / mode->VTotal;
	if (mode->Flags & V_INTERLACE)
	    refresh *= 2.0;
	if (mode->Flags & V_DBLSCAN)
	    refresh /= 2.0;
	if (mode->VScan > 1)
	    refresh /= (float)(mode->VScan);
    }
    return refresh;
}

int
xf86ModeWidth (DisplayModePtr mode, Rotation rotation)
{
    switch (rotation & 0xf) {
    case RR_Rotate_0:
    case RR_Rotate_180:
	return mode->HDisplay;
    case RR_Rotate_90:
    case RR_Rotate_270:
	return mode->VDisplay;
    default:
	return 0;
    }
}

int
xf86ModeHeight (DisplayModePtr mode, Rotation rotation)
{
    switch (rotation & 0xf) {
    case RR_Rotate_0:
    case RR_Rotate_180:
	return mode->VDisplay;
    case RR_Rotate_90:
    case RR_Rotate_270:
	return mode->HDisplay;
    default:
	return 0;
    }
}

/** Sets a default mode name of <width>x<height> on a mode. */
void
xf86SetModeDefaultName(DisplayModePtr mode)
{
    if (mode->name != NULL)
	xfree(mode->name);

    mode->name = XNFprintf("%dx%d", mode->HDisplay, mode->VDisplay);
}

/*
 * xf86SetModeCrtc
 *
 * Initialises the Crtc parameters for a mode.  The initialisation includes
 * adjustments for interlaced and double scan modes.
 *
 * Exact copy of xf86Mode.c's.
 */
void
xf86SetModeCrtc(DisplayModePtr p, int adjustFlags)
{
    if ((p == NULL) || ((p->type & M_T_CRTC_C) == M_T_BUILTIN))
	return;

    p->CrtcHDisplay             = p->HDisplay;
    p->CrtcHSyncStart           = p->HSyncStart;
    p->CrtcHSyncEnd             = p->HSyncEnd;
    p->CrtcHTotal               = p->HTotal;
    p->CrtcHSkew                = p->HSkew;
    p->CrtcVDisplay             = p->VDisplay;
    p->CrtcVSyncStart           = p->VSyncStart;
    p->CrtcVSyncEnd             = p->VSyncEnd;
    p->CrtcVTotal               = p->VTotal;
    if (p->Flags & V_INTERLACE) {
	if (adjustFlags & INTERLACE_HALVE_V) {
	    p->CrtcVDisplay         /= 2;
	    p->CrtcVSyncStart       /= 2;
	    p->CrtcVSyncEnd         /= 2;
	    p->CrtcVTotal           /= 2;
	}
	/* Force interlaced modes to have an odd VTotal */
	/* maybe we should only do this when INTERLACE_HALVE_V is set? */
	p->CrtcVTotal |= 1;
    }

    if (p->Flags & V_DBLSCAN) {
        p->CrtcVDisplay         *= 2;
        p->CrtcVSyncStart       *= 2;
        p->CrtcVSyncEnd         *= 2;
        p->CrtcVTotal           *= 2;
    }
    if (p->VScan > 1) {
        p->CrtcVDisplay         *= p->VScan;
        p->CrtcVSyncStart       *= p->VScan;
        p->CrtcVSyncEnd         *= p->VScan;
        p->CrtcVTotal           *= p->VScan;
    }
    p->CrtcVBlankStart = min(p->CrtcVSyncStart, p->CrtcVDisplay);
    p->CrtcVBlankEnd = max(p->CrtcVSyncEnd, p->CrtcVTotal);
    p->CrtcHBlankStart = min(p->CrtcHSyncStart, p->CrtcHDisplay);
    p->CrtcHBlankEnd = max(p->CrtcHSyncEnd, p->CrtcHTotal);

    p->CrtcHAdjusted = FALSE;
    p->CrtcVAdjusted = FALSE;
}

/**
 * Allocates and returns a copy of pMode, including pointers within pMode.
 */
DisplayModePtr
xf86DuplicateMode(DisplayModePtr pMode)
{
    DisplayModePtr pNew;

    pNew = xnfalloc(sizeof(DisplayModeRec));
    *pNew = *pMode;
    pNew->next = NULL;
    pNew->prev = NULL;
    if (pNew->name == NULL) {
	xf86SetModeDefaultName(pMode);
    } else {
	pNew->name = xnfstrdup(pMode->name);
    }

    return pNew;
}

/**
 * Duplicates every mode in the given list and returns a pointer to the first
 * mode.
 *
 * \param modeList doubly-linked mode list
 */
DisplayModePtr
xf86DuplicateModes(ScrnInfoPtr pScrn, DisplayModePtr modeList)
{
    DisplayModePtr first = NULL, last = NULL;
    DisplayModePtr mode;

    for (mode = modeList; mode != NULL; mode = mode->next) {
	DisplayModePtr new;

	new = xf86DuplicateMode(mode);

	/* Insert pNew into modeList */
	if (last) {
	    last->next = new;
	    new->prev = last;
	} else {
	    first = new;
	    new->prev = NULL;
	}
	new->next = NULL;
	last = new;
    }

    return first;
}

/**
 * Returns true if the given modes should program to the same timings.
 *
 * This doesn't use Crtc values, as it might be used on ModeRecs without the
 * Crtc values set.  So, it's assumed that the other numbers are enough.
 *
 * This isn't in xf86Modes.c, but it might deserve to be there.
 */
Bool
xf86ModesEqual(DisplayModePtr pMode1, DisplayModePtr pMode2)
{
     if (pMode1->Clock == pMode2->Clock &&
	 pMode1->HDisplay == pMode2->HDisplay &&
	 pMode1->HSyncStart == pMode2->HSyncStart &&
	 pMode1->HSyncEnd == pMode2->HSyncEnd &&
	 pMode1->HTotal == pMode2->HTotal &&
	 pMode1->HSkew == pMode2->HSkew &&
	 pMode1->VDisplay == pMode2->VDisplay &&
	 pMode1->VSyncStart == pMode2->VSyncStart &&
	 pMode1->VSyncEnd == pMode2->VSyncEnd &&
	 pMode1->VTotal == pMode2->VTotal &&
	 pMode1->VScan == pMode2->VScan &&
	 pMode1->Flags == pMode2->Flags)
     {
	return TRUE;
     } else {
	return FALSE;
     }
}

/* exact copy of xf86Mode.c */
static void
add(char **p, char *new)
{
    *p = xnfrealloc(*p, strlen(*p) + strlen(new) + 2);
    strcat(*p, " ");
    strcat(*p, new);
}

/**
 * Print out a modeline.
 *
 * Convenient VRefresh printing was added, though, compared to xf86Mode.c
 */
void
xf86PrintModeline(int scrnIndex,DisplayModePtr mode)
{
    char tmp[256];
    char *flags = xnfcalloc(1, 1);

    if (mode->HSkew) { 
	snprintf(tmp, 256, "hskew %i", mode->HSkew); 
	add(&flags, tmp);
    }
    if (mode->VScan) { 
	snprintf(tmp, 256, "vscan %i", mode->VScan); 
	add(&flags, tmp);
    }
    if (mode->Flags & V_INTERLACE) add(&flags, "interlace");
    if (mode->Flags & V_CSYNC) add(&flags, "composite");
    if (mode->Flags & V_DBLSCAN) add(&flags, "doublescan");
    if (mode->Flags & V_BCAST) add(&flags, "bcast");
    if (mode->Flags & V_PHSYNC) add(&flags, "+hsync");
    if (mode->Flags & V_NHSYNC) add(&flags, "-hsync");
    if (mode->Flags & V_PVSYNC) add(&flags, "+vsync");
    if (mode->Flags & V_NVSYNC) add(&flags, "-vsync");
    if (mode->Flags & V_PCSYNC) add(&flags, "+csync");
    if (mode->Flags & V_NCSYNC) add(&flags, "-csync");
#if 0
    if (mode->Flags & V_CLKDIV2) add(&flags, "vclk/2");
#endif
    xf86DrvMsg(scrnIndex, X_INFO,
		   "Modeline \"%s\"x%.01f  %6.2f  %i %i %i %i  %i %i %i %i%s "
		   "(%.01f kHz)\n",
		   mode->name, mode->VRefresh, mode->Clock/1000., mode->HDisplay,
		   mode->HSyncStart, mode->HSyncEnd, mode->HTotal,
		   mode->VDisplay, mode->VSyncStart, mode->VSyncEnd,
		   mode->VTotal, flags, xf86ModeHSync(mode));
    xfree(flags);
}
#endif /* XORG_VERSION_CURRENT <= 7.2.99.2 */

/**
 * Marks as bad any modes with unsupported flags.
 *
 * \param modeList doubly-linked or circular list of modes.
 * \param flags flags supported by the driver.
 *
 * \bug only V_INTERLACE and V_DBLSCAN are supported.  Is that enough?
 *
 * This is not in xf86Modes.c, but would be part of the proposed new API.
 */
void
xf86ValidateModesFlags(ScrnInfoPtr pScrn, DisplayModePtr modeList,
			    int flags)
{
    DisplayModePtr mode;

    for (mode = modeList; mode != NULL; mode = mode->next) {
	if (mode->Flags & V_INTERLACE && !(flags & V_INTERLACE))
	    mode->status = MODE_NO_INTERLACE;
	if (mode->Flags & V_DBLSCAN && !(flags & V_DBLSCAN))
	    mode->status = MODE_NO_DBLESCAN;
    }
}

/**
 * Marks as bad any modes extending beyond the given max X, Y, or pitch.
 *
 * \param modeList doubly-linked or circular list of modes.
 *
 * This is not in xf86Modes.c, but would be part of the proposed new API.
 */
void
xf86ValidateModesSize(ScrnInfoPtr pScrn, DisplayModePtr modeList,
			  int maxX, int maxY, int maxPitch)
{
    DisplayModePtr mode;

    for (mode = modeList; mode != NULL; mode = mode->next) {
	if (maxPitch > 0 && mode->HDisplay > maxPitch)
	    mode->status = MODE_BAD_WIDTH;

	if (maxX > 0 && mode->HDisplay > maxX)
	    mode->status = MODE_VIRTUAL_X;

	if (maxY > 0 && mode->VDisplay > maxY)
	    mode->status = MODE_VIRTUAL_Y;

	if (mode->next == modeList)
	    break;
    }
}

/**
 * Marks as bad any modes that aren't supported by the given monitor's
 * hsync and vrefresh ranges.
 *
 * \param modeList doubly-linked or circular list of modes.
 *
 * This is not in xf86Modes.c, but would be part of the proposed new API.
 */
void
xf86ValidateModesSync(ScrnInfoPtr pScrn, DisplayModePtr modeList,
			  MonPtr mon)
{
    DisplayModePtr mode;

    for (mode = modeList; mode != NULL; mode = mode->next) {
	Bool bad;
	int i;

	bad = TRUE;
	for (i = 0; i < mon->nHsync; i++) {
	    if (xf86ModeHSync(mode) >= mon->hsync[i].lo &&
		xf86ModeHSync(mode) <= mon->hsync[i].hi)
	    {
		bad = FALSE;
	    }
	}
	if (bad)
	    mode->status = MODE_HSYNC;

	bad = TRUE;
	for (i = 0; i < mon->nVrefresh; i++) {
	    if (xf86ModeVRefresh(mode) >= mon->vrefresh[i].lo &&
		xf86ModeVRefresh(mode) <= mon->vrefresh[i].hi)
	    {
		bad = FALSE;
	    }
	}
	if (bad)
	    mode->status = MODE_VSYNC;

	if (mode->next == modeList)
	    break;
    }
}

/**
 * Marks as bad any modes extending beyond outside of the given clock ranges.
 *
 * \param modeList doubly-linked or circular list of modes.
 * \param min pointer to minimums of clock ranges
 * \param max pointer to maximums of clock ranges
 * \param n_ranges number of ranges.
 *
 * This is not in xf86Modes.c, but would be part of the proposed new API.
 */
void
xf86ValidateModesClocks(ScrnInfoPtr pScrn, DisplayModePtr modeList,
			    int *min, int *max, int n_ranges)
{
    DisplayModePtr mode;
    int i;

    for (mode = modeList; mode != NULL; mode = mode->next) {
	Bool good = FALSE;
	for (i = 0; i < n_ranges; i++) {
	    if (mode->Clock >= min[i] && mode->Clock <= max[i]) {
		good = TRUE;
		break;
	    }
	}
	if (!good)
	    mode->status = MODE_CLOCK_RANGE;
    }
}

/**
 * If the user has specified a set of mode names to use, mark as bad any modes
 * not listed.
 *
 * The user mode names specified are prefixes to names of modes, so "1024x768"
 * will match modes named "1024x768", "1024x768x75", "1024x768-good", but
 * "1024x768x75" would only match "1024x768x75" from that list.
 *
 * MODE_BAD is used as the rejection flag, for lack of a better flag.
 *
 * \param modeList doubly-linked or circular list of modes.
 *
 * This is not in xf86Modes.c, but would be part of the proposed new API.
 */
void
xf86ValidateModesUserConfig(ScrnInfoPtr pScrn, DisplayModePtr modeList)
{
    DisplayModePtr mode;

    if (pScrn->display->modes[0] == NULL)
	return;

    for (mode = modeList; mode != NULL; mode = mode->next) {
	int i;
	Bool good = FALSE;

	for (i = 0; pScrn->display->modes[i] != NULL; i++) {
	    if (strncmp(pScrn->display->modes[i], mode->name,
			strlen(pScrn->display->modes[i])) == 0) {
		good = TRUE;
		break;
	    }
	}
	if (!good)
	    mode->status = MODE_BAD;
    }
}


/**
 * Frees any modes from the list with a status other than MODE_OK.
 *
 * \param modeList pointer to a doubly-linked or circular list of modes.
 * \param verbose determines whether the reason for mode invalidation is
 *	  printed.
 *
 * This is not in xf86Modes.c, but would be part of the proposed new API.
 */
void
xf86PruneInvalidModes(ScrnInfoPtr pScrn, DisplayModePtr *modeList,
			  Bool verbose)
{
    DisplayModePtr mode;

    for (mode = *modeList; mode != NULL;) {
	DisplayModePtr next = mode->next, first = *modeList;

	if (mode->status != MODE_OK) {
	    if (verbose) {
		char *type = "";
		if (mode->type & M_T_BUILTIN)
		    type = "built-in ";
		else if (mode->type & M_T_DEFAULT)
		    type = "default ";
		xf86DrvMsg(pScrn->scrnIndex, X_INFO,
			   "Not using %smode \"%s\" (%s)\n", type, mode->name,
			   xf86ModeStatusToString(mode->status));
	    }
	    xf86DeleteMode(modeList, mode);
	}

	if (next == first)
	    break;
	mode = next;
    }
}

/**
 * Adds the new mode into the mode list, and returns the new list
 *
 * \param modes doubly-linked mode list.
 */
DisplayModePtr
xf86ModesAdd(DisplayModePtr modes, DisplayModePtr new)
{
    if (modes == NULL)
	return new;

    if (new) {
	DisplayModePtr mode = modes;

	while (mode->next)
	    mode = mode->next;

	mode->next = new;
	new->prev = mode;
    }

    return modes;
}

/**
 * Build a mode list from a list of config file modes
 */
static DisplayModePtr
xf86GetConfigModes (XF86ConfModeLinePtr conf_mode)
{
    DisplayModePtr  head = NULL, prev = NULL, mode;
    
    for (; conf_mode; conf_mode = (XF86ConfModeLinePtr) conf_mode->list.next)
    {
        mode = xcalloc(1, sizeof(DisplayModeRec));
	if (!mode)
	    continue;
        mode->name       = xstrdup(conf_mode->ml_identifier);
	if (!mode->name)
	{
	    xfree (mode);
	    continue;
	}
	mode->type       = 0;
        mode->Clock      = conf_mode->ml_clock;
        mode->HDisplay   = conf_mode->ml_hdisplay;
        mode->HSyncStart = conf_mode->ml_hsyncstart;
        mode->HSyncEnd   = conf_mode->ml_hsyncend;
        mode->HTotal     = conf_mode->ml_htotal;
        mode->VDisplay   = conf_mode->ml_vdisplay;
        mode->VSyncStart = conf_mode->ml_vsyncstart;
        mode->VSyncEnd   = conf_mode->ml_vsyncend;
        mode->VTotal     = conf_mode->ml_vtotal;
        mode->Flags      = conf_mode->ml_flags;
        mode->HSkew      = conf_mode->ml_hskew;
        mode->VScan      = conf_mode->ml_vscan;

        mode->prev = prev;
	mode->next = NULL;
	if (prev)
	    prev->next = mode;
	else
	    head = mode;
	prev = mode;
    }
    return head;
}

/**
 * Build a mode list from a monitor configuration
 */
DisplayModePtr
xf86GetMonitorModes (ScrnInfoPtr pScrn, XF86ConfMonitorPtr conf_monitor)
{
    DisplayModePtr	    modes = NULL;
    XF86ConfModesLinkPtr    modes_link;
    
    if (!conf_monitor)
	return NULL;

    /*
     * first we collect the mode lines from the UseModes directive
     */
    for (modes_link = conf_monitor->mon_modes_sect_lst; 
	 modes_link; 
	 modes_link = modes_link->list.next)
    {
	/* If this modes link hasn't been resolved, go look it up now */
	if (!modes_link->ml_modes)
	    modes_link->ml_modes = xf86findModes (modes_link->ml_modes_str, 
						  xf86configptr->conf_modes_lst);
	if (modes_link->ml_modes)
	    modes = xf86ModesAdd (modes,
				  xf86GetConfigModes (modes_link->ml_modes->mon_modeline_lst));
    }

    return xf86ModesAdd (modes,
			 xf86GetConfigModes (conf_monitor->mon_modeline_lst));
}

/**
 * Build a mode list containing all of the default modes
 */
DisplayModePtr
xf86GetDefaultModes (Bool interlaceAllowed, Bool doubleScanAllowed)
{
    DisplayModePtr  head = NULL, prev = NULL, mode;
    int		    i;

    for (i = 0; xf86DefaultModes[i].name != NULL; i++)
    {
	DisplayModePtr	defMode = &xf86DefaultModes[i];
	
	if (!interlaceAllowed && (defMode->Flags & V_INTERLACE))
	    continue;
	if (!doubleScanAllowed && (defMode->Flags & V_DBLSCAN))
	    continue;

	mode = xalloc(sizeof(DisplayModeRec));
	if (!mode)
	    continue;
        memcpy(mode,&xf86DefaultModes[i],sizeof(DisplayModeRec));
        mode->name = xstrdup(xf86DefaultModes[i].name);
        if (!mode->name)
	{
	    xfree (mode);
	    continue;
	}
        mode->prev = prev;
	mode->next = NULL;
	if (prev)
	    prev->next = mode;
	else
	    head = mode;
	prev = mode;
    }
    return head;
}