drm/rockchip: fix fbdev on non-IOMMU devices

[ Upstream commit ab78c74cfc5a3caa2bbb7627cb8f3bca40bb5fb0 ]

When switching to the generic fbdev infrastructure, it was missed that
framebuffers were created with the alloc_kmap parameter to
rockchip_gem_create_object() set to true.  The generic infrastructure
calls this via the .dumb_create() driver operation and thus creates a
buffer without an associated kmap.

alloc_kmap only makes a difference on devices without an IOMMU, but when
it is missing rockchip_gem_prime_vmap() fails and the framebuffer cannot
be used.

Detect the case where a buffer is being allocated for the framebuffer
and ensure a kernel mapping is created in this case.

Fixes: 24af7c34b290 ("drm/rockchip: use generic fbdev setup")
Reported-by: Johan Jonker <jbx6244@gmail.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20221020181248.2497065-1-john@metanate.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index 985584147da10f4cb9685dee052854e04ff2cc99..cf8322c300bd5e660d92143234ca3c7a06f66740 100644 (file)
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -364,9 +364,12 @@ rockchip_gem_create_with_handle(struct drm_file *file_priv,
 {
        struct rockchip_gem_object *rk_obj;
        struct drm_gem_object *obj;
+       bool is_framebuffer;
        int ret;
 
-       rk_obj = rockchip_gem_create_object(drm, size, false);
+       is_framebuffer = drm->fb_helper && file_priv == drm->fb_helper->client.file;
+
+       rk_obj = rockchip_gem_create_object(drm, size, is_framebuffer);
        if (IS_ERR(rk_obj))
                return ERR_CAST(rk_obj);