[Mesa-dev] [RFC 3/5] platform/android: Enable kms_swrast fallback

[Robert Foss]

Add support for the ForceSoftware option, which is togglable
on the Android platform through setting the "drm.gpu.force_software"
property to a non-zero value.

kms_swrast is also enabled as a fallback for when a driver is not
able to be loaded for for a drm node that was opened.

Signed-off-by: Robert Foss <robert.foss at collabora.com>
---
 src/egl/drivers/dri2/platform_android.c | 26 +++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/src/egl/drivers/dri2/platform_android.c b/src/egl/drivers/dri2/platform_android.c
index 92b2d2b343e..bc644c25bf9 100644
--- a/src/egl/drivers/dri2/platform_android.c
+++ b/src/egl/drivers/dri2/platform_android.c
@@ -1193,17 +1193,21 @@ static const __DRIextension *droid_image_loader_extensions[] = {
 };
 
 EGLBoolean
-droid_load_driver(_EGLDisplay *disp)
+droid_load_driver(_EGLDisplay *disp, EGLBoolean force_software)
 {
    struct dri2_egl_display *dri2_dpy = disp->DriverData;
    const char *err;
 
-   dri2_dpy->driver_name = loader_get_driver_for_fd(dri2_dpy->fd);
+   if (force_software) {
+      dri2_dpy->driver_name = strdup("kms_swrast");
+   } else {
+      dri2_dpy->driver_name = loader_get_driver_for_fd(dri2_dpy->fd);
+   }
+
    if (dri2_dpy->driver_name == NULL)
       return false;
 
    dri2_dpy->is_render_node = drmGetNodeTypeFromFd(dri2_dpy->fd) == DRM_NODE_RENDER;
-
    if (!dri2_dpy->is_render_node) {
    #ifdef HAVE_DRM_GRALLOC
        /* Handle control nodes using __DRI_DRI2_LOADER extension and GEM names
@@ -1359,6 +1363,7 @@ EGLBoolean
 dri2_initialize_android(_EGLDriver *drv, _EGLDisplay *disp)
 {
    struct dri2_egl_display *dri2_dpy;
+   int force_software = disp->Options.ForceSoftware;
    const char *err;
    int ret;
 
@@ -1384,13 +1389,18 @@ dri2_initialize_android(_EGLDriver *drv, _EGLDisplay *disp)
 
    dri2_dpy->fd = droid_open_device(disp);
    if (dri2_dpy->fd < 0) {
-      err = "DRI2: failed to open device";
-      goto cleanup;
+      err = "DRI2: failed to open device, trying software device";
    }
 
-   if (!droid_load_driver(disp)) {
-      err = "DRI2: failed to load driver";
-      goto cleanup;
+load_driver:
+   if (!droid_load_driver(disp, force_software)) {
+      if (force_software) {
+         err = "DRI2: failed to load driver";
+         goto cleanup;
+      } else {
+         force_software = true;
+         goto load_driver;
+      }
    }
 
    if (!dri2_create_screen(disp)) {
-- 
2.17.1