vaGetDeviceNames inspired fixes and documentation

va/va.c

@@ -674,10 +674,6 @@ static VAStatus va_new_opendriver(VADisplay dpy)
     const char *driver_name_env;
     VADriverContextP ctx;
 
-    /* XXX: Temporary dummy return, until all platforms are converted */
-    if (!pDisplayContext->vaGetDriverNames)
-        return VA_STATUS_ERROR_INVALID_PARAMETER;
-
     /* XXX: The order is bonkers - env var should take highest priority, then
      * override (which ought to be nuked) than native. It's not possible atm,
      * since the DPY connect/init happens during the GetDriverNames.
@@ -687,9 +683,6 @@ static VAStatus va_new_opendriver(VADisplay dpy)
         /* Print and error yet continue, as per the above ordering note */
         va_errorMessage(dpy, "vaGetDriverNames() failed with %s\n", vaErrorStr(vaStatus));
         num_drivers = 0;
-    } else if (num_drivers > ARRAY_SIZE(drivers)) {
-        va_errorMessage(dpy, "DRIVER BUG: vaGetDriverNames() provides too many drivers\n");
-        num_drivers = ARRAY_SIZE(drivers);
     }
 
     ctx = CTX(dpy);

va/va_backend.h

@@ -663,30 +663,51 @@ struct VADisplayContext {
         VADisplayContextP ctx
     );
 
+    /* Deprecated */
     VAStatus(*vaGetDriverName)(
         VADisplayContextP ctx,
         char **driver_name
     );
 
     void *opaque; /* opaque for display extensions (e.g. GLX) */
     void *vatrace; /* opaque for VA trace context */
+    /* Deprecated */
     void *vafool; /* opaque for VA fool context */
 
     VAMessageCallback error_callback;
     void *error_callback_user_context;
     VAMessageCallback info_callback;
     void *info_callback_user_context;
+
+    /* Deprecated */
     VAStatus(*vaGetNumCandidates)(
         VADisplayContextP ctx,
         int * num_candidates
     );
 
+    /* Deprecated */
     VAStatus(*vaGetDriverNameByIndex)(
         VADisplayContextP ctx,
         char **driver_name,
         int  candidate_index
     );
 
+    /**
+     * \brief Callback to get an array of driver names.
+     *
+     *
+     * The caller must provide a num_drivers
+     * This structure is allocated from libva with calloc().
+     *
+     * @param drivers  An num_drivers sized array of null terminated strings.
+     *                 The array is managed my the caller. The callee will
+     *                 populate the individual driver name strings and the
+     *                 caller must free them.
+     * @param num_driver The number of driver strings contained within drivers.
+     *                   The caller must set that to the size of the drivers
+     *                   array, where the callee will update the value to
+     *                   min(caller num_driver, num_drivers_support).
+     */
     VAStatus(*vaGetDriverNames)(
         VADisplayContextP ctx,
         char **drivers,

va/win32/va_win32.c

@@ -38,18 +38,17 @@
 const char VAAPI_DEFAULT_DRIVER_NAME[] = "vaon12";
 
 typedef struct _VADisplayContextWin32 {
-    LUID adapter_luid;
     char registry_driver_name[MAX_PATH];
     bool registry_driver_available_flag;
 } VADisplayContextWin32;
 
-static void LoadDriverNameFromRegistry(VADisplayContextWin32* pWin32Ctx)
+static void LoadDriverNameFromRegistry(const LUID* adapter_luid, VADisplayContextWin32* pWin32Ctx)
 {
     HMODULE hGdi32 = LoadLibraryA("gdi32.dll");
     if (!hGdi32)
         return;
 
-    D3DKMT_OPENADAPTERFROMLUID OpenArgs = { .AdapterLuid = pWin32Ctx->adapter_luid };
+    D3DKMT_OPENADAPTERFROMLUID OpenArgs = { .AdapterLuid = *adapter_luid };
     D3DDDI_QUERYREGISTRY_INFO RegistryInfo = {
         .QueryType = D3DDDI_QUERYREGISTRY_ADAPTERKEY,
         .QueryFlags.TranslatePath = true,
@@ -180,16 +179,13 @@ VADisplay vaGetDisplayWin32(
 
     VADisplayContextWin32* pWin32Ctx = (VADisplayContextWin32*) pDisplayContext->opaque;
     if (adapter_luid) {
-        /* Copy LUID information to display context */
-        memcpy(&pWin32Ctx->adapter_luid, adapter_luid, sizeof(pWin32Ctx->adapter_luid));
-
         /* Load the preferred driver name from the driver registry if available */
-        LoadDriverNameFromRegistry(pWin32Ctx);
+        LoadDriverNameFromRegistry(adapter_luid, pWin32Ctx);
 #ifdef _DEBUG
         if (pWin32Ctx->registry_driver_available_flag) {
-            fprintf(stderr, "VA_Win32: Found driver %s in the registry for LUID %ld %ld \n", pWin32Ctx->registry_driver_name, pWin32Ctx->adapter_luid.LowPart, pWin32Ctx->adapter_luid.HighPart);
+            fprintf(stderr, "VA_Win32: Found driver %s in the registry for LUID %ld %ld \n", pWin32Ctx->registry_driver_name, adapter_luid.LowPart, adapter_luid.HighPart);
         } else {
-            fprintf(stderr, "VA_Win32: Couldn't find a driver in the registry for LUID %ld %ld. Using default driver: %s \n", pWin32Ctx->adapter_luid.LowPart, pWin32Ctx->adapter_luid.HighPart, VAAPI_DEFAULT_DRIVER_NAME);
+            fprintf(stderr, "VA_Win32: Couldn't find a driver in the registry for LUID %ld %ld. Using default driver: %s \n", adapter_luid.LowPart, adapter_luid.HighPart, VAAPI_DEFAULT_DRIVER_NAME);
         }
 #endif // _DEBUG
     }

va/x11/va_dri2.c

@@ -456,11 +456,9 @@ VAStatus va_DRI2_GetDriverNames(
         if (strcmp(map[i].dri_driver, dri_driver) == 0) {
             const char * const *va_drivers = map[i].va_driver;
 
-            while (va_drivers[count]) {
-                if (count < MAX_NAMES && count < *num_drivers)
-                    drivers[count] = strdup(va_drivers[count]);
-                count++;
-            }
+            for (; count < MAX_NAMES && va_drivers[count] && count < *num_drivers; count++)
+                drivers[count] = strdup(va_drivers[count]);
+
             break;
         }
     }