dp: scope virtual sink caps to forced connectors

src/common/displayport/inc/dp_configcaps.h

@@ -305,6 +305,8 @@ namespace DisplayPort
         virtual void overrideOptimalLinkRate(LinkRate optimalLinkRate) = 0;
 
         virtual bool isDpcdOffline() = 0;
+        virtual bool isVirtualSinkDpcdFallback() = 0;
+        virtual void setVirtualSinkDpcdFallback(bool bEnable) = 0;
         virtual void setAuxBus(AuxBus * bus) = 0;
         virtual NvU32 getVideoFallbackSupported() = 0;
         //
@@ -596,6 +598,7 @@ namespace DisplayPort
         AuxRetry  bus;
         Timer    * timer;
         bool      dpcdOffline;
+        bool      bVirtualSinkDpcdFallback;
         bool      bGrantsPostLtRequest;
         bool      pc2Disabled;
         bool      uprequestEnable;
@@ -795,7 +798,8 @@ namespace DisplayPort
 
         public:
         DPCDHALImpl(AuxBus * bus, Timer * timer)
-        : bus(bus), timer(timer), bGrantsPostLtRequest(false), uprequestEnable(false),
+        : bus(bus), timer(timer), bVirtualSinkDpcdFallback(false),
+          bGrantsPostLtRequest(false), uprequestEnable(false),
           upstreamIsSource(false), bMultistream(false), bGpuFECSupported(false),
           bBypassILREdpRevCheck(false), overrideDpcdMaxLinkRate(0),
           overrideDpcdRev(0), gpuDPSupportedVersions(0)
@@ -834,6 +838,16 @@ namespace DisplayPort
             return dpcdOffline;
         }
 
+        bool isVirtualSinkDpcdFallback()
+        {
+            return bVirtualSinkDpcdFallback;
+        }
+
+        void setVirtualSinkDpcdFallback(bool bEnable)
+        {
+            bVirtualSinkDpcdFallback = bEnable;
+        }
+
         void setDPCDOffline(bool bOffline)
         {
             dpcdOffline = bOffline;

src/common/displayport/inc/dp_connector.h

@@ -630,6 +630,7 @@ namespace DisplayPort
 
         // Notify library of hotplug/IRQ
         virtual void notifyLongPulse(bool statusConnected) = 0;
+        virtual void notifyVirtualSinkLongPulse(bool statusConnected) = 0;
         virtual void notifyShortPulse() = 0;
 
         // Notify Library when ACPI initialization is done

src/common/displayport/inc/dp_connectorimpl.h

@@ -760,6 +760,7 @@ namespace DisplayPort
         virtual void disconnectDeviceList();
         void notifyLongPulseInternal(bool statusConnected);
         virtual void notifyLongPulse(bool status);
+        virtual void notifyVirtualSinkLongPulse(bool status);
         virtual void notifyShortPulse();
         virtual Group * newGroup();
         virtual void destroy();

src/common/displayport/src/dp_configcaps.cpp

@@ -185,11 +185,21 @@ void DPCDHALImpl::parseAndReadCaps()
         // Set an invalid state here and make sure we REMEMBER we couldn't get the caps
         caps.revisionMajor = 0;
         dpcdOffline = true;
+        if (bVirtualSinkDpcdFallback)
+        {
+            //
+            // Forced/sink-less connector (EDID override, no AUX): fall back to
+            // fake caps so discovery can proceed and create a device.
+            //
+            populateFakeDpcd();
+            caps.revisionMinor = 0x4;
+        }
         return;
     }
 
     // reset the faked dpcd flag since real LT should be possible now.
     dpcdOffline = false;
+    bVirtualSinkDpcdFallback = false;
 
     // reset edp revision to 0
     caps.eDpRevision = 0;
@@ -634,6 +644,14 @@ bool DPCDHALImpl::getSDPExtnForColorimetry()
 {
     bool bSDPExtnForColorimetry = false;
     NvU8 byte = 0;
+    if (dpcdOffline && bVirtualSinkDpcdFallback)
+    {
+        //
+        // Forced/sink-less connector: claim VSC SDP colorimetry support so
+        // HDR signaling can be enabled. No real sink interprets the SDP.
+        //
+        return true;
+    }
     if (caps.extendedRxCapsPresent)
     {
         if (AuxRetry::ack == bus.read(NV_DPCD14_EXTENDED_DPRX_FEATURE_ENUM_LIST, &byte,  sizeof byte))
@@ -3180,4 +3198,3 @@ DPCDHAL * DisplayPort::MakeDPCDHAL(AuxBus *  bus, Timer * timer, MainLink * main
         return new DPCDHALImpl(bus, timer);
     }
 }
-

src/common/displayport/src/dp_connectorimpl.cpp

@@ -7348,6 +7348,7 @@ void ConnectorImpl::notifyLongPulse(bool statusConnected)
 {
     NvU32 muxState = 0;
     NV_DPTRACE_INFO(HOTPLUG, statusConnected, connectorActive, previousPlugged);
+    hal->setVirtualSinkDpcdFallback(false);
 
     if (!connectorActive)
     {
@@ -7427,6 +7428,18 @@ void ConnectorImpl::notifyLongPulse(bool statusConnected)
     this->notifyLongPulseInternal(statusConnected);
 }
 
+void ConnectorImpl::notifyVirtualSinkLongPulse(bool statusConnected)
+{
+    if (!connectorActive)
+    {
+        DP_PRINTF(DP_ERROR, "DP> Got a virtual-sink long pulse before any connector is active!!");
+        return;
+    }
+
+    hal->setVirtualSinkDpcdFallback(statusConnected);
+    this->notifyLongPulseInternal(statusConnected);
+}
+
 /*!
  * @brief Compute the max BW required across all devices and try to allocate that BW
  *
@@ -9313,4 +9326,3 @@ void ConnectorImpl::ensureMstNodesPoweredUp(Group * target)
         }
     }
 }
-

src/common/displayport/src/dp_deviceimpl.cpp

@@ -1732,6 +1732,15 @@ NvBool DeviceImpl::getDSCSupport()
         }
     }
 
+    else if (hal->isVirtualSinkDpcdFallback())
+    {
+        //
+        // Forced/sink-less connector (EDID override, no AUX): assume the
+        // virtual sink can decompress DSC so that high-bandwidth modes pass
+        // validation. The stream is never decoded by a real device.
+        //
+        dscCaps.bDSCDecompressionSupported = true;
+    }
     else
     {
         DP_PRINTF(DP_ERROR, "DP-DEV> DSC Support AUX READ failed for %s!", address.toString(sb));
@@ -2308,6 +2317,12 @@ bool DeviceImpl::getFECSupport()
         bFECSupported = this->bandwidth.enum_path.bPathFECCapable;
     }
 
+    else if (hal->isVirtualSinkDpcdFallback())
+    {
+        // Forced/sink-less connector: claim FEC so the DSC path is usable.
+        bFECSupported = true;
+    }
+
     else if (AuxBus::success == this->getDpcdData(NV_DPCD14_FEC_CAPABILITY,
         &byte, sizeof(byte), &size, &nakReason))
     {
@@ -2560,6 +2575,30 @@ bool DeviceImpl::readAndParseDSCCaps()
     if(AuxBus::success != this->getDpcdData(NV_DPCD14_DSC_SUPPORT,
         &rawDscCaps[0], sizeof(rawDscCaps), &sizeCompleted, &nakReason))
     {
+        if (hal->isVirtualSinkDpcdFallback())
+        {
+            //
+            // Forced/sink-less connector: synthesize DSC decoder caps
+            // modeled on a typical DSC 1.2 4K high-refresh monitor.
+            //
+            rawDscCaps[0x0] = 0x01; // decompression supported
+            rawDscCaps[0x1] = 0x21; // DSC algorithm revision 1.2
+            rawDscCaps[0x2] = 0x00; // RC buffer block size
+            rawDscCaps[0x3] = 0x0F; // RC buffer size
+            rawDscCaps[0x4] = 0xFF; // slice caps 1: up to 12 slices
+            rawDscCaps[0x5] = 0x03; // line buffer bit depth: 12
+            rawDscCaps[0x6] = 0x01; // block prediction supported
+            rawDscCaps[0x7] = 0xFF; // max bits per pixel LSB
+            rawDscCaps[0x8] = 0x03; // max bits per pixel MSB (1023/16 bpp)
+            rawDscCaps[0x9] = 0x1F; // color formats: RGB + all YCbCr
+            rawDscCaps[0xA] = 0x0E; // color depth: 8/10/12 bpc
+            rawDscCaps[0xB] = 0xEE; // peak throughput 1000 MP/s both modes
+            rawDscCaps[0xC] = 0x10; // max slice width 5120 px
+            rawDscCaps[0xD] = 0x00; // slice caps 2
+            rawDscCaps[0xE] = 0x00; // branch throughput
+            rawDscCaps[0xF] = 0x00; // bpp increment: 1/16
+            return parseDscCaps(&rawDscCaps[0], sizeof(rawDscCaps));
+        }
         DP_PRINTF(DP_ERROR, "DP-DEV> Error querying DSC Caps on %s!", this->address.toString(sb));
         return false;
     }

src/nvidia-modeset/include/dp/nvdp-connector.h

@@ -35,8 +35,13 @@ NVDPLibConnectorPtr nvDPCreateConnector(NVConnectorEvoPtr pConnectorEvo);
 void nvDPNotifyLongPulse(NVConnectorEvoPtr pConnectorEvo,
                          NvBool connected);
 
+void nvDPNotifyVirtualSinkLongPulse(NVConnectorEvoPtr pConnectorEvo,
+                                    NvBool connected);
+
 void nvDPNotifyShortPulse(NVDPLibConnectorPtr pNVDpLibConnector);
 
+NvBool nvDPConnectorIsPlugged(const NVConnectorEvoRec *pConnectorEvo);
+
 void nvDPDestroyConnector(NVDPLibConnectorPtr pNVDpLibConnector);
 
 NVDPLibModesetStatePtr nvDPLibCreateModesetState(

src/nvidia-modeset/src/dp/nvdp-connector.cpp

@@ -121,6 +121,22 @@ void nvDPNotifyLongPulse(NVConnectorEvoPtr pConnectorEvo,
 
 }
 
+void nvDPNotifyVirtualSinkLongPulse(NVConnectorEvoPtr pConnectorEvo,
+                                    NvBool connected)
+{
+    NVDPLibConnectorPtr pNVDpLibConnector = pConnectorEvo->pDpLibConnector;
+    DisplayPort::Connector *c = pNVDpLibConnector->connector;
+
+    pNVDpLibConnector->plugged = connected;
+    c->notifyVirtualSinkLongPulse(connected);
+}
+
+NvBool nvDPConnectorIsPlugged(const NVConnectorEvoRec *pConnectorEvo)
+{
+    return (pConnectorEvo->pDpLibConnector != NULL) &&
+           pConnectorEvo->pDpLibConnector->plugged;
+}
+
 void nvDPNotifyShortPulse(NVDPLibConnectorPtr pNVDpLibConnector)
 {
     DisplayPort::Connector *c = pNVDpLibConnector->connector;

src/nvidia-modeset/src/nvkms-dpy.c

@@ -22,6 +22,7 @@
  */
 
 #include "dp/nvdp-device.h"
+#include "dp/nvdp-connector.h"
 #include "dp/nvdp-connector-event-sink.h"
 
 #include "nvkms-api-types.h"
@@ -3127,6 +3128,15 @@ NvBool nvDpyGetDynamicData(
         connectedList = nvDPLibDpyIsConnected(pDpyEvo) ?
             oneDpyIdList : nvEmptyDpyIdList();
     } else if (pRequest->forceConnected) {
+        if (nvConnectorUsesDPLib(pConnectorEvo) &&
+            !nvDPConnectorIsPlugged(pConnectorEvo)) {
+            /*
+             * Forced sink-less DP connector (EDID override): simulate a
+             * virtual-sink plug so DPLib performs discovery with fake DPCD
+             * caps scoped to this explicit force-connected path.
+             */
+            nvDPNotifyVirtualSinkLongPulse(pConnectorEvo, TRUE);
+        }
         connectedList = oneDpyIdList;
     } else if (pRequest->forceDisconnected) {
         connectedList = nvEmptyDpyIdList();