present: fallback get_crtc to return crtc belonging to screen with present extension

Since crtc can belong to secondary output that may not have present
extension enabled we should fallback to first enabled crtc or fake crtc.

Fix for issue xorg/xserver#1195

2 files changed, 29 insertions, 0 deletions

diff --git a/randr/randr.c b/randr/randr.c
index 3f94c2f6c..6d02c2577 100644
--- a/randr/randr.c
+++ b/randr/randr.c
@@ -697,6 +697,33 @@ RRFirstOutput(ScreenPtr pScreen)
     return NULL;
 }
 
+RRCrtcPtr
+RRFirstEnabledCrtc(ScreenPtr pScreen)
+{
+    rrScrPriv(pScreen);
+    RROutputPtr output;
+    int i, j;
+
+    if (!pScrPriv)
+        return NULL;
+
+    if (pScrPriv->primaryOutput && pScrPriv->primaryOutput->crtc &&
+        pScrPriv->primaryOutput->pScreen == pScreen)
+        return pScrPriv->primaryOutput->crtc;
+
+    for (i = 0; i < pScrPriv->numCrtcs; i++) {
+        RRCrtcPtr crtc = pScrPriv->crtcs[i];
+
+        for (j = 0; j < pScrPriv->numOutputs; j++) {
+            output = pScrPriv->outputs[j];
+            if (output->crtc == crtc && crtc->mode)
+                return crtc;
+        }
+    }
+    return NULL;
+}
+
+
 CARD16
 RRVerticalRefresh(xRRModeInfo * mode)
 {
diff --git a/randr/randrstr.h b/randr/randrstr.h
index 8f427a48e..b23390575 100644
--- a/randr/randrstr.h
+++ b/randr/randrstr.h
@@ -593,6 +593,8 @@ extern _X_EXPORT Bool RRScreenInit(ScreenPtr pScreen);
 
 extern _X_EXPORT RROutputPtr RRFirstOutput(ScreenPtr pScreen);
 
+extern _X_EXPORT RRCrtcPtr RRFirstEnabledCrtc(ScreenPtr pScreen);
+
 extern _X_EXPORT Bool RROutputSetNonDesktop(RROutputPtr output, Bool non_desktop);
 
 extern _X_EXPORT CARD16