From b3f3a097bc6f2fb1f4ef9bcbcd5641c33851fea3 Mon Sep 17 00:00:00 2001
From: stefan11111 <stefan11111@shitposting.expert>
Date: Wed, 17 Dec 2025 02:52:56 +0200
Subject: [PATCH] gbm: Implement dmabuf import using dumb buffers only

Split from https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/38646

The dmabuf import code will never get called for now,
since the dri backend will not be initialized
if only dumb buffers can be created.

Signed-off-by: stefan11111 <stefan11111@shitposting.expert>
---
 src/gbm/backends/dri/gbm_dri.c | 45 ++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/src/gbm/backends/dri/gbm_dri.c b/src/gbm/backends/dri/gbm_dri.c
index fcb13d4532f..b71244f0e76 100644
--- a/src/gbm/backends/dri/gbm_dri.c
+++ b/src/gbm/backends/dri/gbm_dri.c
@@ -676,6 +676,43 @@ gbm_dri_bo_destroy(struct gbm_bo *_bo)
    free(bo);
 }
 
+static struct gbm_bo *
+dumb_bo_from_fd(struct gbm_device *gbm,
+                struct gbm_import_fd_data *fd_data)
+{
+#ifdef HAVE_LIBDRM
+   struct gbm_dri_bo *bo;
+   int ret;
+   uint32_t handle;
+
+   bo = calloc(1, sizeof *bo);
+   if (bo == NULL) {
+      errno = ENOMEM;
+      return NULL;
+   }
+
+   ret = drmPrimeFDToHandle(gbm->v0.fd, fd_data->fd, &handle);
+   if (ret) {
+      free(bo);
+      return NULL;
+   }
+
+   bo->base.gbm = gbm;
+   bo->base.v0.width = fd_data->width;
+   bo->base.v0.height = fd_data->height;
+   bo->base.v0.stride = fd_data->stride;
+   bo->base.v0.format = fd_data->format;
+   bo->base.v0.handle.u32 = handle;
+   bo->handle = handle;
+   bo->size = fd_data->stride * fd_data->height;
+
+   return &bo->base;
+#else
+   errno = ENOSYS;
+   return NULL;
+#endif
+}
+
 static struct gbm_bo *
 gbm_dri_bo_import(struct gbm_device *gbm,
                   uint32_t type, void *buffer, uint32_t usage)
@@ -750,6 +787,9 @@ gbm_dri_bo_import(struct gbm_device *gbm,
        * the sARGB format. */
       fourcc = core->v0.format_canonicalize(fd_data->format);
 
+      if (!dri->screen)
+         return dumb_bo_from_fd(gbm, fd_data);
+
       image = dri2_from_dma_bufs(dri->screen,
                                  fd_data->width,
                                  fd_data->height,
@@ -778,6 +818,11 @@ gbm_dri_bo_import(struct gbm_device *gbm,
        * the sARGB format. */
       fourcc = core->v0.format_canonicalize(fd_data->format);
 
+      if (!dri->screen) {
+         errno = EINVAL;
+         return NULL;
+      }
+
       image = dri2_from_dma_bufs(dri->screen, fd_data->width,
                                                  fd_data->height, fourcc,
                                                  fd_data->modifier,