Commit b43e2ec0 authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/vkms: Let shadow-plane helpers prepare the plane's FB 



Replace vkms' prepare_fb and cleanup_fb functions with the generic
code for shadow-buffered planes. No functional changes.

This change also fixes a problem where IGT kms_flip tests would
create a segmentation fault within vkms. The driver's prepare_fb
function did not report an error if a BO's vmap operation failed.
The kernel later tried to operate on the non-mapped memory areas.
The shared shadow-plane helpers handle errors correctly, so that
the driver now avoids the segmantation fault.

v2:
	* include paragraph about IGT tests in commit message (Melissa)

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarMelissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210705074633.9425-4-tzimmermann@suse.de
parent 7602d422

drivers/gpu/drm/vkms/vkms_plane.c

+1 −37
Original line number Diff line number Diff line
@@ -8,7 +8,6 @@ 
#include <drm/drm_gem_atomic_helper.h>

#include <drm/drm_gem_framebuffer_helper.h>

#include <drm/drm_plane_helper.h>

#include <drm/drm_gem_shmem_helper.h>



#include "vkms_drv.h"
@@ -150,45 +149,10 @@ static int vkms_plane_atomic_check(struct drm_plane *plane, 
	return 0;

}



static int vkms_prepare_fb(struct drm_plane *plane,

			   struct drm_plane_state *state)

{

	struct drm_gem_object *gem_obj;

	struct dma_buf_map map;

	int ret;



	if (!state->fb)

		return 0;



	gem_obj = drm_gem_fb_get_obj(state->fb, 0);

	ret = drm_gem_shmem_vmap(gem_obj, &map);

	if (ret)

		DRM_ERROR("vmap failed: %d\n", ret);



	return drm_gem_plane_helper_prepare_fb(plane, state);

}



static void vkms_cleanup_fb(struct drm_plane *plane,

			    struct drm_plane_state *old_state)

{

	struct drm_gem_object *gem_obj;

	struct drm_gem_shmem_object *shmem_obj;

	struct dma_buf_map map;



	if (!old_state->fb)

		return;



	gem_obj = drm_gem_fb_get_obj(old_state->fb, 0);

	shmem_obj = to_drm_gem_shmem_obj(drm_gem_fb_get_obj(old_state->fb, 0));

	dma_buf_map_set_vaddr(&map, shmem_obj->vaddr);

	drm_gem_shmem_vunmap(gem_obj, &map);

}



static const struct drm_plane_helper_funcs vkms_primary_helper_funcs = {

	.atomic_update		= vkms_plane_atomic_update,

	.atomic_check		= vkms_plane_atomic_check,

	.prepare_fb		= vkms_prepare_fb,

	.cleanup_fb		= vkms_cleanup_fb,

	DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,

};



struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,