enable driver candidate select fucntion for DRM

add multiple backend driver support part 3
enable vaGetDriverNameByIndex for DRM
add comments for the implementation
mv authenticate operation into vaGetNumCandidates function
from vaGetDriverName.

Signed-off-by: Carl Zhang <carl.zhang@intel.com>

6 files changed, 108 insertions, 25 deletions

diff --git a/va/android/va_android.cpp b/va/android/va_android.cpp
index c49d3f3..4b5d81e 100644
--- a/va/android/va_android.cpp
+++ b/va/android/va_android.cpp
@@ -100,9 +100,10 @@ static void va_DisplayContextDestroy (
     free(pDisplayContext);
 }
 
-static VAStatus va_DisplayContextGetDriverName (
+}
+static VAStatus va_DisplayContextGetNumCandidates(
     VADisplayContextP pDisplayContext,
-    char **driver_name
+    int *num_candidates
 )
 {
     VADriverContextP const ctx = pDisplayContext->pDriverContext;
@@ -116,8 +117,18 @@ static VAStatus va_DisplayContextGetDriverName (
         return VA_STATUS_ERROR_UNKNOWN;
     }
     drm_state->auth_type = VA_DRM_AUTH_CUSTOM;
+    return VA_DRM_GetNumCandidates(ctx, num_candidates);
+}
+
+static VAStatus va_DisplayContextGetDriverNameByIndex (
+    VADisplayContextP pDisplayContext,
+    char **driver_name,
+    int candidate_index
+)
+{
+    VADriverContextP const ctx = pDisplayContext->pDriverContext;
 
-    return VA_DRM_GetDriverName(ctx, driver_name);
+    return VA_DRM_GetDriverName(ctx, driver_name, candidate_index);
 }
 
 
@@ -138,7 +149,8 @@ VADisplay vaGetDisplay (
 
     pDisplayContext->vaIsValid       = va_DisplayContextIsValid;
     pDisplayContext->vaDestroy       = va_DisplayContextDestroy;
-    pDisplayContext->vaGetDriverName = va_DisplayContextGetDriverName;
+    pDisplayContext->vaGetDriverNameByIndex = va_DisplayContextGetDriverNameByIndex;
+    pDisplayContext->vaGetNumCandidates = va_DisplayContextGetNumCandidates;
 
     pDriverContext = va_newDriverContext(pDisplayContext);
     if (!pDriverContext) {
diff --git a/va/drm/va_drm.c b/va/drm/va_drm.c
index b406e68..c135a0f 100644
--- a/va/drm/va_drm.c
+++ b/va/drm/va_drm.c
@@ -51,24 +51,19 @@ va_DisplayContextDestroy(VADisplayContextP pDisplayContext)
     free(pDisplayContext->pDriverContext);
     free(pDisplayContext);
 }
-
-static VAStatus
-va_DisplayContextGetDriverName(
+static VAStatus va_DisplayContextGetNumCandidates(
     VADisplayContextP pDisplayContext,
-    char            **driver_name_ptr
+    int *num_candidates
 )
 {
-
     VADriverContextP const ctx = pDisplayContext->pDriverContext;
     struct drm_state * const drm_state = ctx->drm_state;
+    VAStatus status = VA_STATUS_SUCCESS;
     drm_magic_t magic;
-    VAStatus status;
     int ret;
-
-    status = VA_DRM_GetDriverName(ctx, driver_name_ptr);
+    status = VA_DRM_GetNumCandidates(ctx, num_candidates);
     if (status != VA_STATUS_SUCCESS)
         return status;
-
     /* Authentication is only needed for a legacy DRM device */
     if (ctx->display_type != VA_DISPLAY_DRM_RENDERNODES) {
         ret = drmGetMagic(drm_state->fd, &magic);
@@ -80,10 +75,22 @@ va_DisplayContextGetDriverName(
     }
 
     drm_state->auth_type = VA_DRM_AUTH_CUSTOM;
-
     return VA_STATUS_SUCCESS;
 }
 
+static VAStatus
+va_DisplayContextGetDriverNameByIndex(
+    VADisplayContextP pDisplayContext,
+    char            **driver_name_ptr,
+    int               candidate_index
+)
+{
+
+    VADriverContextP const ctx = pDisplayContext->pDriverContext;
+
+    return VA_DRM_GetDriverName(ctx, driver_name_ptr, candidate_index);
+}
+
 VADisplay
 vaGetDisplayDRM(int fd)
 {
@@ -108,7 +115,8 @@ vaGetDisplayDRM(int fd)
 
     pDisplayContext->vaIsValid       = va_DisplayContextIsValid;
     pDisplayContext->vaDestroy       = va_DisplayContextDestroy;
-    pDisplayContext->vaGetDriverName = va_DisplayContextGetDriverName;
+    pDisplayContext->vaGetNumCandidates = va_DisplayContextGetNumCandidates;
+    pDisplayContext->vaGetDriverNameByIndex = va_DisplayContextGetDriverNameByIndex;
 
     pDriverContext = va_newDriverContext(pDisplayContext);
     if (!pDriverContext)
diff --git a/va/drm/va_drm_utils.c b/va/drm/va_drm_utils.c
index cd67ecb..905ccdd 100644
--- a/va/drm/va_drm_utils.c
+++ b/va/drm/va_drm_utils.c
@@ -48,14 +48,39 @@ static const struct driver_name_map g_driver_name_map[] = {
     { NULL,         0, NULL }
 };
 
+/* Returns the VA driver candidate num for the active display*/
+VAStatus
+VA_DRM_GetNumCandidates(VADriverContextP ctx, int * num_candidates)
+{
+    struct drm_state * const drm_state = ctx->drm_state;
+    drmVersionPtr drm_version;
+    int num_of_candidate = 0;
+    const struct driver_name_map *m = NULL;
+    if (!drm_state || drm_state->fd < 0)
+        return VA_STATUS_ERROR_INVALID_DISPLAY;
+    drm_version = drmGetVersion(drm_state->fd);
+    if (!drm_version)
+        return VA_STATUS_ERROR_UNKNOWN;
+    for (m = g_driver_name_map; m->key != NULL; m++) {
+        if (drm_version->name_len >= m->key_len &&
+            strncmp(drm_version->name, m->key, m->key_len) == 0) {
+            num_of_candidate ++;
+        }
+    }
+    drmFreeVersion(drm_version);
+    *num_candidates = num_of_candidate;
+    return VA_STATUS_SUCCESS;
+}
+
 /* Returns the VA driver name for the active display */
 VAStatus
-VA_DRM_GetDriverName(VADriverContextP ctx, char **driver_name_ptr)
+VA_DRM_GetDriverName(VADriverContextP ctx, char **driver_name_ptr, int candidate_index)
 {
     struct drm_state * const drm_state = ctx->drm_state;
     drmVersionPtr drm_version;
     char *driver_name = NULL;
     const struct driver_name_map *m;
+    int current_index = 0;
 
     *driver_name_ptr = NULL;
 
@@ -68,8 +93,12 @@ VA_DRM_GetDriverName(VADriverContextP ctx, char **driver_name_ptr)
 
     for (m = g_driver_name_map; m->key != NULL; m++) {
         if (drm_version->name_len >= m->key_len &&
-            strncmp(drm_version->name, m->key, m->key_len) == 0)
-            break;
+            strncmp(drm_version->name, m->key, m->key_len) == 0) {
+            if (current_index == candidate_index) {
+                break;
+            }
+            current_index ++;
+        }
     }
     drmFreeVersion(drm_version);
 
diff --git a/va/drm/va_drm_utils.h b/va/drm/va_drm_utils.h
index b468c59..1e9d90c 100644
--- a/va/drm/va_drm_utils.h
+++ b/va/drm/va_drm_utils.h
@@ -41,7 +41,9 @@
 #ifdef __cplusplus
 extern "C" {
 #endif
-
+DLL_HIDDEN
+VAStatus
+VA_DRM_GetNumCandidates(VADriverContextP ctx, int * num_candidates);
 /**
  * \brief Returns the VA driver name for the active display.
  *
@@ -62,7 +64,7 @@ extern "C" {
  */
 DLL_HIDDEN
 VAStatus
-VA_DRM_GetDriverName(VADriverContextP ctx, char **driver_name_ptr);
+VA_DRM_GetDriverName(VADriverContextP ctx, char **driver_name_ptr, int candidate_index);
 
 /**
  * \brief Checks whether the file descriptor is a DRM Render-Nodes one
diff --git a/va/va.c b/va/va.c
index 952cfd9..cfcabff 100644
--- a/va/va.c
+++ b/va/va.c
@@ -341,7 +341,9 @@ va_getDriverInitName(char *name, int namelen, int major, int minor)
     int ret = snprintf(name, namelen, "__vaDriverInit_%d_%d", major, minor);
     return ret > 0 && ret < namelen;
 }
-
+/** retrieve the back end driver candidate num , by default it should be 1
+  * if there are no vaGetNumCandidates implementation in the display context
+  * it should be 1 to avoid backward compatible issue */
 static VAStatus va_getDriverNumCandidates(VADisplay dpy, int *num_candidates)
 {
     VADisplayContextP pDisplayContext = (VADisplayContextP)dpy;
@@ -368,7 +370,7 @@ static VAStatus va_getDriverNameByIndex(VADisplay dpy, char **driver_name, int c
 
     ctx = CTX(dpy);
     driver_name_env = getenv("LIBVA_DRIVER_NAME");
-
+    /*if user set driver name by vaSetDriverName */
     if (ctx->override_driver_name){
         *driver_name = strdup(ctx->override_driver_name);
         if (!(*driver_name)) {
@@ -378,10 +380,12 @@ static VAStatus va_getDriverNameByIndex(VADisplay dpy, char **driver_name, int c
         va_infoMessage(dpy, "User requested driver '%s'\n", *driver_name);
         return VA_STATUS_SUCCESS;
     } else if (driver_name_env && (geteuid() == getuid())) {
+        /*if user set driver name by environment variable*/
         *driver_name = strdup(driver_name_env);
         va_infoMessage(dpy, "User environment variable requested driver '%s'\n", *driver_name);
         return VA_STATUS_SUCCESS;
     } else if (pDisplayContext->vaGetDriverNameByIndex) {
+        /*if vaGetDriverNameByIndex is implemented*/
         return pDisplayContext->vaGetDriverNameByIndex(pDisplayContext, driver_name, candidate_index);
     } else {
         if (candidate_index == 0)
@@ -713,12 +717,15 @@ VAStatus vaInitialize (
     va_MessagingInit();
 
     va_infoMessage(dpy, "VA-API version %s\n", VA_VERSION_S);
-
+    /*get backend driver candidate number, by default the value should be 1*/
     vaStatus = va_getDriverNumCandidates(dpy, &num_candidates);
     if (vaStatus != VA_STATUS_SUCCESS) {
         num_candidates = 1;
     }
+    /*load driver one by one, until load success */
     for (candidate_index = 0; candidate_index < num_candidates; candidate_index ++) {
+        if(driver_name)
+            free(driver_name);
         vaStatus = va_getDriverNameByIndex(dpy, &driver_name, candidate_index);
         if(vaStatus != VA_STATUS_SUCCESS) {
             va_errorMessage(dpy, "vaGetDriverNameByIndex() failed with %s, driver_name = %s\n", vaErrorStr(vaStatus), driver_name);
@@ -729,7 +736,7 @@ VAStatus vaInitialize (
 
         if (vaStatus == VA_STATUS_SUCCESS) {
             break;
-        }
+       }
         
     }
 
diff --git a/va/wayland/va_wayland_drm.c b/va/wayland/va_wayland_drm.c
index 4cd3f6c..aebddcc 100644
--- a/va/wayland/va_wayland_drm.c
+++ b/va/wayland/va_wayland_drm.c
@@ -117,6 +117,29 @@ static const struct wl_drm_listener drm_listener = {
 };
 
 static VAStatus
+va_DisplayContextGetNumCandidates(
+    VADisplayContextP pDisplayContext,
+    int *candidate_index
+)
+{
+    VADriverContextP const ctx = pDisplayContext->pDriverContext;
+
+    return VA_DRM_GetNumCandidates(ctx, candidate_index);
+}
+
+static VAStatus
+va_DisplayContextGetDriverNameByIndex(
+    VADisplayContextP pDisplayContext,
+    char            **driver_name_ptr,
+    int             candidate_index
+)
+{
+    VADriverContextP const ctx = pDisplayContext->pDriverContext;
+
+    return VA_DRM_GetDriverName(ctx, driver_name_ptr, candidate_index);
+}
+
+static VAStatus
 va_DisplayContextGetDriverName(
     VADisplayContextP pDisplayContext,
     char            **driver_name_ptr
@@ -124,7 +147,7 @@ va_DisplayContextGetDriverName(
 {
     VADriverContextP const ctx = pDisplayContext->pDriverContext;
 
-    return VA_DRM_GetDriverName(ctx, driver_name_ptr);
+    return VA_DRM_GetDriverName(ctx, driver_name_ptr, 0);
 }
 
 void
@@ -237,6 +260,8 @@ va_wayland_drm_create(VADisplayContextP pDisplayContext)
     wl_drm_ctx->is_authenticated        = 0;
     pDisplayContext->opaque             = wl_drm_ctx;
     pDisplayContext->vaGetDriverName    = va_DisplayContextGetDriverName;
+    pDisplayContext->vaGetNumCandidates  = va_DisplayContextGetNumCandidates;
+    pDisplayContext->vaGetDriverNameByIndex = va_DisplayContextGetDriverNameByIndex;
 
     drm_state = calloc(1, sizeof(struct drm_state));
     if (!drm_state) {