From cb83fbdfa22aa408e6692256cd44b78fef53e801 Mon Sep 17 00:00:00 2001
From: Aaron Plattner <aplattner@nvidia.com>
Date: Fri, 9 May 2008 18:31:07 -0700
Subject: [PATCH] Add an option to allow validation of dual-link DVI modes.

These modes don't work at bootup (i.e. power saving) configuration on all GPUs,
so they're still disabled by default.  This option allows users to enable them
in case they actually work.
---
 man/nv.man       |  4 ++++
 src/g80_driver.c | 13 ++++++++-----
 src/g80_sor.c    |  7 ++++---
 src/g80_type.h   |  1 +
 4 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/man/nv.man b/man/nv.man
index 7a08823..19816bd 100644
--- a/man/nv.man
+++ b/man/nv.man
@@ -162,6 +162,10 @@ Default: XAA.
 Enable or disable flat panel dithering by default.
 Dithering can also be enabled or disabled using the RandR 1.2 \*qdither\*q output property.
 Default: off.
+.TP
+.BI "Option \*qAllowDualLinkModes\*q \*q" boolean \*q
+Allow validation of dual-link DVI modes.
+Not all GPUs are configured at boot time to be able to handle dual-link modes, so they are disabled by default.
 .
 .\" RandR 1.2
 .PP
diff --git a/src/g80_driver.c b/src/g80_driver.c
index 99ea737..a0182a1 100644
--- a/src/g80_driver.c
+++ b/src/g80_driver.c
@@ -106,14 +106,16 @@ typedef enum {
     OPTION_NOACCEL,
     OPTION_ACCEL_METHOD,
     OPTION_FP_DITHER,
+    OPTION_ALLOW_DUAL_LINK,
 } G80Opts;
 
 static const OptionInfoRec G80Options[] = {
-    { OPTION_HW_CURSOR,         "HWCursor",     OPTV_BOOLEAN,   {0}, FALSE },
-    { OPTION_NOACCEL,           "NoAccel",      OPTV_BOOLEAN,   {0}, FALSE },
-    { OPTION_ACCEL_METHOD,      "AccelMethod",  OPTV_STRING,    {0}, FALSE },
-    { OPTION_FP_DITHER,         "FPDither",     OPTV_BOOLEAN,   {0}, FALSE },
-    { -1,                       NULL,           OPTV_NONE,      {0}, FALSE }
+    { OPTION_HW_CURSOR,         "HWCursor",             OPTV_BOOLEAN,   {0}, FALSE },
+    { OPTION_NOACCEL,           "NoAccel",              OPTV_BOOLEAN,   {0}, FALSE },
+    { OPTION_ACCEL_METHOD,      "AccelMethod",          OPTV_STRING,    {0}, FALSE },
+    { OPTION_FP_DITHER,         "FPDither",             OPTV_BOOLEAN,   {0}, FALSE },
+    { OPTION_ALLOW_DUAL_LINK,   "AllowDualLinkModes",   OPTV_BOOLEAN,   {0}, FALSE },
+    { -1,                       NULL,                   OPTV_NONE,      {0}, FALSE }
 };
 
 static Bool
@@ -331,6 +333,7 @@ G80PreInit(ScrnInfoPtr pScrn, int flags)
     }
 
     pNv->Dither = xf86ReturnOptValBool(pNv->Options, OPTION_FP_DITHER, FALSE);
+    pNv->AllowDualLink = xf86ReturnOptValBool(pNv->Options, OPTION_ALLOW_DUAL_LINK, FALSE);
 
     /* Set the bits per RGB for 8bpp mode */
     if(pScrn->depth == 8)
diff --git a/src/g80_sor.c b/src/g80_sor.c
index 02a5f3b..202e838 100644
--- a/src/g80_sor.c
+++ b/src/g80_sor.c
@@ -69,9 +69,10 @@ G80SorDPMSSet(xf86OutputPtr output, int mode)
 static int
 G80TMDSModeValid(xf86OutputPtr output, DisplayModePtr mode)
 {
-    // Disable dual-link modes until I can find a way to make them work
-    // reliably.
-    if (mode->Clock > 165000)
+    G80Ptr pNv = G80PTR(output->scrn);
+
+    // Disable dual-link modes unless enabled in the config file.
+    if (mode->Clock > 165000 && !pNv->AllowDualLink)
         return MODE_CLOCK_HIGH;
 
     return G80OutputModeValid(output, mode);
diff --git a/src/g80_type.h b/src/g80_type.h
index 5f4ee08..30ef3fe 100644
--- a/src/g80_type.h
+++ b/src/g80_type.h
@@ -67,6 +67,7 @@ typedef struct G80Rec {
     Bool                NoAccel;
     AccelMethod         AccelMethod;
     Bool                Dither;
+    Bool                AllowDualLink;
 
     /* XAA */
     XAAInfoRecPtr       xaa;