Allow RandR get output property to call into drivers

In order to report accurate values to users of the RandR property interface,
it's sometimes necessary to ask the driver to update the value (for example
when backlight brightness changes without the server's knowledge, due to hotkey
events or direct sysfs banging).

This patch wires up the core server code with a new xf86CrtcFuncs callback,
get_property, to allow for this.

The new code is available under the RANDR_13_INTERFACE define, which in turn
depends on the RANDR_12_INTERFACE code.

hw/xfree86/modes/xf86Crtc.h

@@ -215,7 +215,14 @@ typedef struct _xf86CrtcFuncs {
 		      Rotation rotation, int x, int y);
 } xf86CrtcFuncsRec, *xf86CrtcFuncsPtr;
 
+#define XF86_CRTC_VERSION 1
+
 struct _xf86Crtc {
+    /**
+     * ABI versioning
+     */
+    int version;
+
     /**
      * Associated ScrnInfo
      */
@@ -409,6 +416,14 @@ typedef struct _xf86OutputFuncs {
     (*set_property)(xf86OutputPtr output,
 		    Atom property,
 		    RRPropertyValuePtr value);
+#endif
+#ifdef RANDR_13_INTERFACE
+    /**
+     * Callback to get an updated property value
+     */
+    Bool
+    (*get_property)(xf86OutputPtr output,
+		    Atom property);
 #endif
     /**
      * Clean up driver-specific bits of the output
@@ -417,7 +432,15 @@ typedef struct _xf86OutputFuncs {
     (*destroy) (xf86OutputPtr	    output);
 } xf86OutputFuncsRec, *xf86OutputFuncsPtr;
 
+
+#define XF86_OUTPUT_VERSION 1
+
 struct _xf86Output {
+    /**
+     * ABI versioning
+     */
+    int version;
+
     /**
      * Associated ScrnInfo
      */

hw/xfree86/modes/xf86RandR12.c

@@ -847,6 +847,20 @@ xf86RandR12OutputSetProperty (ScreenPtr pScreen,
     return output->funcs->set_property(output, property, value);
 }
 
+static Bool
+xf86RandR13OutputGetProperty (ScreenPtr pScreen,
+			      RROutputPtr randr_output,
+			      Atom property)
+{
+    xf86OutputPtr output = randr_output->devPrivate;
+
+    if (output->funcs->get_property == NULL)
+	return TRUE;
+
+    /* Should be safe even w/o vtSema */
+    return output->funcs->get_property(output, property);
+}
+
 static Bool
 xf86RandR12OutputValidateMode (ScreenPtr    pScreen,
 			       RROutputPtr  randr_output,
@@ -1126,6 +1140,9 @@ xf86RandR12Init12 (ScreenPtr pScreen)
     rp->rrCrtcSetGamma = xf86RandR12CrtcSetGamma;
     rp->rrOutputSetProperty = xf86RandR12OutputSetProperty;
     rp->rrOutputValidateMode = xf86RandR12OutputValidateMode;
+#if RANDR_13_INTERFACE
+    rp->rrOutputGetProperty = xf86RandR13OutputGetProperty;
+#endif
     rp->rrModeDestroy = xf86RandR12ModeDestroy;
     rp->rrSetConfig = NULL;
     pScrn->PointerMoved = xf86RandR12PointerMoved;

randr/mirandr.c

@@ -73,6 +73,14 @@ miRROutputSetProperty (ScreenPtr	    pScreen,
     return TRUE;
 }
 
+Bool
+miRROutputGetProperty (ScreenPtr	    pScreen,
+		       RROutputPtr	    output,
+		       Atom		    property)
+{
+	return TRUE;
+}
+
 Bool
 miRROutputValidateMode (ScreenPtr	    pScreen,
 			RROutputPtr	    output,
@@ -116,6 +124,9 @@ miRandRInit (ScreenPtr pScreen)
     pScrPriv->rrCrtcSet = miRRCrtcSet;
     pScrPriv->rrCrtcSetGamma = miRRCrtcSetGamma;
     pScrPriv->rrOutputSetProperty = miRROutputSetProperty;
+#if RANDR_13_INTERFACE
+    pScrPriv->rrOutputGetProperty = miRROutputGetProperty;
+#endif
     pScrPriv->rrOutputValidateMode = miRROutputValidateMode;
     pScrPriv->rrModeDestroy = miRRModeDestroy;
     

randr/randrstr.h

@@ -54,6 +54,7 @@
 /* required for ABI compatibility for now */
 #define RANDR_10_INTERFACE 1
 #define RANDR_12_INTERFACE 1
+#define RANDR_13_INTERFACE 1 /* requires RANDR_12_INTERFACE */
 
 typedef XID	RRMode;
 typedef XID	RROutput;
@@ -175,6 +176,12 @@ typedef void (*RRModeDestroyProcPtr) (ScreenPtr	    pScreen,
 
 #endif
 
+#if RANDR_13_INTERFACE
+typedef Bool (*RROutputGetPropertyProcPtr) (ScreenPtr		pScreen,
+					    RROutputPtr		output,
+					    Atom		property);
+#endif /* RANDR_13_INTERFACE */
+
 typedef Bool (*RRGetInfoProcPtr) (ScreenPtr pScreen, Rotation *rotations);
 typedef Bool (*RRCloseScreenProcPtr) ( int i, ScreenPtr pscreen);
 
@@ -220,6 +227,9 @@ typedef struct _rrScrPriv {
     RROutputValidateModeProcPtr	rrOutputValidateMode;
     RRModeDestroyProcPtr	rrModeDestroy;
 #endif
+#if RANDR_13_INTERFACE
+    RROutputGetPropertyProcPtr	rrOutputGetProperty;
+#endif
     
     /*
      * Private part of the structure; not considered part of the ABI

randr/rrproperty.c

@@ -300,13 +300,21 @@ RRPropertyValuePtr
 RRGetOutputProperty (RROutputPtr output, Atom property, Bool pending)
 {
     RRPropertyPtr   prop = RRQueryOutputProperty (output, property);
+    rrScrPrivPtr    pScrPriv = rrGetScrPriv(output->pScreen);
 
     if (!prop)
 	return NULL;
     if (pending && prop->is_pending)
 	return &prop->pending;
-    else
+    else {
+#if RANDR_13_INTERFACE
+	/* If we can, try to update the property value first */
+	if (pScrPriv->rrOutputGetProperty)
+	    pScrPriv->rrOutputGetProperty(output->pScreen, output,
+					  prop->propertyName);
+#endif
 	return &prop->current;
+    }
 }
 
 int
@@ -610,10 +618,9 @@ ProcRRGetOutputProperty (ClientPtr client)
     if (prop->immutable && stuff->delete)
 	return BadAccess;
 
-    if (stuff->pending && prop->is_pending)
-	prop_value = &prop->pending;
-    else
-	prop_value = &prop->current;
+    prop_value = RRGetOutputProperty(output, stuff->property, stuff->pending);
+    if (!prop_value)
+	return BadAtom;
 
     /* If the request type and actual type don't match. Return the
     property information, but not the data. */