Don't skip over the 4 descriptors in base EDID block

2 files changed, 79 insertions, 70 deletions

diff --git a/src/xprivate.cpp b/src/xprivate.cpp
index 4be7098..2cba1b0 100644
--- a/src/xprivate.cpp
+++ b/src/xprivate.cpp
@@ -247,10 +247,13 @@ void XPrivate::addMissingEdidResolutions()
 		unsigned long edidLen = 512;
 		if (!getEdid(resptr->outputs[i], prop, &edidLen))
 			continue;
-		if (edidLen < 256)
+		if (edidLen < 128)
 			continue;
+		for (unsigned int j = 54; j < 125; j+= 18) {
+			addMissingModesFromDtd(resptr, resptr->outputs[i], prop + j);
+		}
 		for (unsigned int j = 128; j < edidLen - 127; j += 128) {
-			addMissingModesFromEdid(resptr, resptr->outputs[i], prop + j);
+			addMissingModesFromExtBlock(resptr, resptr->outputs[i], prop + j);
 		}
 	}
 	XRRFreeScreenResources(resptr);
@@ -319,7 +322,7 @@ bool XPrivate::readEdid(OutputInfo* output)
 		return true;
 }
 
-void XPrivate::addMissingModesFromEdid(XRRScreenResources *res, RROutput outputId, unsigned char *data)
+void XPrivate::addMissingModesFromExtBlock(XRRScreenResources *res, RROutput outputId, unsigned char *data)
 {
 	if (data[0] != 2) // Not type 2, skip
 		return;
@@ -332,79 +335,84 @@ void XPrivate::addMissingModesFromEdid(XRRScreenResources *res, RROutput outputI
 		dtdOffset = 128;
 	}
 
-	int hactive, vactive, pixclk, hsyncoff, hsyncwidth, hblank, vsyncoff, vsyncwidth, vblank;
 	for (int i = dtdOffset; i < 128 - 17; i += 18) {
-		if (data[i] == 0 && data[i + 1] == 0)
-			continue;
-		hactive = data[i+2] + ((data[i+4] & 0xf0) << 4);
-		hblank = data[i+3] + ((data[i+4] & 0x0f) << 8);
-		vactive = data[i+5] + ((data[i+7] & 0xf0) << 4);
-		vblank = data[i+6] + ((data[i+7] & 0x0f) << 8);
-		pixclk = (data[i+1] << 8) | (data[i]); // 10kHz
-		hsyncoff = data[i+8] | ((data[i+11] & 0xC0) << 2);
-		hsyncwidth = data[i+9] | ((data[i+11] & 0x30) << 4);
-		vsyncoff = ((data[i+10] & 0xf0) >> 4) | ((data[i+11] & 0x0C) << 2);
-		vsyncwidth = (data[i+10] & 0x0f) | ((data[i+11] & 0x03) << 4);
-		char buf[100];
-		XRRModeInfo m;
-		memset(&m, 0, sizeof(m));
-		m.width     = static_cast<unsigned int>(hactive);
-		m.height    = static_cast<unsigned int>(vactive);
-		m.dotClock  = static_cast<unsigned long>(pixclk) * 10ul * 1000ul;
-		m.hSyncStart= static_cast<unsigned int>(hactive + hsyncoff);
-		m.hSyncEnd  = static_cast<unsigned int>(hactive + hsyncoff + hsyncwidth);
-		m.hTotal    = static_cast<unsigned int>(hactive + hblank);
-		m.hSkew     = 0;
-		m.vSyncStart= static_cast<unsigned int>(vactive + vsyncoff);
-		m.vSyncEnd  = static_cast<unsigned int>(vactive + vsyncoff + vsyncwidth);
-		m.vTotal    = static_cast<unsigned int>(vactive + vblank);
-		m.id        = 0;
-		m.name = buf;
-		m.nameLength = static_cast<unsigned int>(snprintf(buf, sizeof(buf), "%dx%d_%d", hactive, vactive, static_cast<int>(m.dotClock / (m.hTotal * m.vTotal))));
-		if (m.nameLength > sizeof(buf)) {
-			m.nameLength = sizeof(buf);
-		}
-		if ((data[i+17] & 0x18) == 0x18) {
-			// Digital Separate
-			if (data[i+17] & 0x04) {
-				m.modeFlags |= RR_VSyncPositive;
-			} else {
-				m.modeFlags |= RR_VSyncNegative;
-			}
-			if (data[i+17] & 0x02) {
-				m.modeFlags |= RR_HSyncPositive;
-			} else {
-				m.modeFlags |= RR_HSyncNegative;
-			}
-		} else if ((data[i+17] & 0x18) == 0x10) {
-			// Digital Composite
-			if (data[i+17] & 0x02) {
-				m.modeFlags |= RR_HSyncPositive;
-			} else {
-				m.modeFlags |= RR_HSyncNegative;
-			}
-			m.modeFlags |= RR_VSyncNegative; // Default? Clarify...
+		addMissingModesFromDtd(res, outputId, data + i);
+	}
+}
+
+void XPrivate::addMissingModesFromDtd(XRRScreenResources *res, RROutput outputId, unsigned char *data)
+{
+	if (data[0] == 0 && data[1] == 0)
+		return;
+	int hactive, vactive, pixclk, hsyncoff, hsyncwidth, hblank, vsyncoff, vsyncwidth, vblank;
+	hactive = data[2] + ((data[4] & 0xf0) << 4);
+	hblank = data[3] + ((data[4] & 0x0f) << 8);
+	vactive = data[5] + ((data[7] & 0xf0) << 4);
+	vblank = data[6] + ((data[7] & 0x0f) << 8);
+	pixclk = (data[1] << 8) | (data[0]); // 10kHz
+	hsyncoff = data[8] | ((data[11] & 0xC0) << 2);
+	hsyncwidth = data[9] | ((data[11] & 0x30) << 4);
+	vsyncoff = ((data[10] & 0xf0) >> 4) | ((data[11] & 0x0C) << 2);
+	vsyncwidth = (data[10] & 0x0f) | ((data[11] & 0x03) << 4);
+	char buf[100];
+	XRRModeInfo m;
+	memset(&m, 0, sizeof(m));
+	m.width     = static_cast<unsigned int>(hactive);
+	m.height    = static_cast<unsigned int>(vactive);
+	m.dotClock  = static_cast<unsigned long>(pixclk) * 10ul * 1000ul;
+	m.hSyncStart= static_cast<unsigned int>(hactive + hsyncoff);
+	m.hSyncEnd  = static_cast<unsigned int>(hactive + hsyncoff + hsyncwidth);
+	m.hTotal    = static_cast<unsigned int>(hactive + hblank);
+	m.hSkew     = 0;
+	m.vSyncStart= static_cast<unsigned int>(vactive + vsyncoff);
+	m.vSyncEnd  = static_cast<unsigned int>(vactive + vsyncoff + vsyncwidth);
+	m.vTotal    = static_cast<unsigned int>(vactive + vblank);
+	m.id        = 0;
+	m.name = buf;
+	m.nameLength = static_cast<unsigned int>(snprintf(buf, sizeof(buf), "%dx%d_%d", hactive, vactive, static_cast<int>(m.dotClock / (m.hTotal * m.vTotal))));
+	if (m.nameLength > sizeof(buf)) {
+		m.nameLength = sizeof(buf);
+	}
+	if ((data[17] & 0x18) == 0x18) {
+		// Digital Separate
+		if (data[17] & 0x04) {
+			m.modeFlags |= RR_VSyncPositive;
 		} else {
-			m.modeFlags |= RR_VSyncNegative | RR_HSyncNegative; // ...
-		}
-		if (data[i+17] & 0x80) {
-			m.modeFlags |= RR_Interlace;
+			m.modeFlags |= RR_VSyncNegative;
 		}
-		// See if we should add this mode
-		RRMode modeId = 0;
-		for (int mode = 0; mode < res->nmode; ++mode) {
-			if (modeEqual(&res->modes[mode], &m)) {
-				modeId = res->modes[mode].id;
-				break;
-			}
+		if (data[17] & 0x02) {
+			m.modeFlags |= RR_HSyncPositive;
+		} else {
+			m.modeFlags |= RR_HSyncNegative;
 		}
-		if (modeId == 0) {
-			modeId = XRRCreateMode(_display, DefaultRootWindow(_display), &m);
+	} else if ((data[17] & 0x18) == 0x10) {
+		// Digital Composite
+		if (data[17] & 0x02) {
+			m.modeFlags |= RR_HSyncPositive;
+		} else {
+			m.modeFlags |= RR_HSyncNegative;
 		}
-		if (modeId != 0) {
-			XRRAddOutputMode(_display, outputId, modeId);
+		m.modeFlags |= RR_VSyncNegative; // Default? Clarify...
+	} else {
+		m.modeFlags |= RR_VSyncNegative | RR_HSyncNegative; // ...
+	}
+	if (data[17] & 0x80) {
+		m.modeFlags |= RR_Interlace;
+	}
+	// See if we should add this mode
+	RRMode modeId = 0;
+	for (int mode = 0; mode < res->nmode; ++mode) {
+		if (modeEqual(&res->modes[mode], &m)) {
+			modeId = res->modes[mode].id;
+			break;
 		}
 	}
+	if (modeId == 0) {
+		modeId = XRRCreateMode(_display, DefaultRootWindow(_display), &m);
+	}
+	if (modeId != 0) {
+		XRRAddOutputMode(_display, outputId, modeId);
+	}
 }
 
 void XPrivate::setScreenSize(const QSize &size)
diff --git a/src/xprivate.h b/src/xprivate.h
index 28234ac..3bc6067 100644
--- a/src/xprivate.h
+++ b/src/xprivate.h
@@ -47,7 +47,8 @@ public:
 	void         addMissingEdidResolutions();
 	bool         getEdid(RROutput outputId, unsigned char *buffer, unsigned long *size);
 	bool         readEdid(OutputInfo* output);
-	void         addMissingModesFromEdid(XRRScreenResources *res, RROutput outputId, unsigned char *data);
+	void         addMissingModesFromExtBlock(XRRScreenResources *res, RROutput outputId, unsigned char *data);
+	void         addMissingModesFromDtd(XRRScreenResources *res, RROutput outputId, unsigned char *data);
     void         disconnectAllCrtcs();
     XRRModeInfo* getPreferredMode(OutputInfo *oi, XRRModeInfo *fallback = nullptr) const;
     void         setScreenSize(const QSize &size);