drm/mgag200: Remove HW cursor

The HW cursor of Matrox G200 cards only supports a 16-color palette
format. Univeral planes require at least ARGB or a similar component-
based format, so remove the HW cursor.

Alternatively, the driver could dither a cursor image from ARGB to
16 colors. But this does not produce pleasent-looking results in
general, so it's useless for modern compositors.

Without HW support, compositors will use software rendering.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: John Donnelly <John.p.donnelly@oracle.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Emil Velikov <emil.velikov@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200515083233.32036-2-tzimmermann@suse.de

drivers/gpu/drm/mgag200/Makefile

 # SPDX-License-Identifier: GPL-2.0-only
-mgag200-y   := mgag200_main.o mgag200_mode.o mgag200_cursor.o \
+mgag200-y   := mgag200_main.o mgag200_mode.o \
 	mgag200_drv.o mgag200_i2c.o mgag200_ttm.o
 
 obj-$(CONFIG_DRM_MGAG200) += mgag200.o

drivers/gpu/drm/mgag200/mgag200_drv.h

@@ -116,11 +116,6 @@ struct mga_connector {
 	struct mga_i2c_chan *i2c;
 };
 
-struct mga_cursor {
-	struct drm_gem_vram_object *gbo[2];
-	unsigned int next_index;
-};
-
 struct mga_mc {
 	resource_size_t			vram_size;
 	resource_size_t			vram_base;
@@ -156,8 +151,6 @@ struct mga_device {
 
 	struct mga_mc			mc;
 
-	struct mga_cursor cursor;
-
 	size_t vram_fb_available;
 
 	bool				suspended;
@@ -207,10 +200,4 @@ int mgag200_mm_init(struct mga_device *mdev);
 void mgag200_mm_fini(struct mga_device *mdev);
 int mgag200_mmap(struct file *filp, struct vm_area_struct *vma);
 
-int mgag200_cursor_init(struct mga_device *mdev);
-void mgag200_cursor_fini(struct mga_device *mdev);
-int mgag200_crtc_cursor_set(struct drm_crtc *crtc, struct drm_file *file_priv,
-			    uint32_t handle, uint32_t width, uint32_t height);
-int mgag200_crtc_cursor_move(struct drm_crtc *crtc, int x, int y);
-
 #endif				/* __MGAG200_DRV_H__ */

drivers/gpu/drm/mgag200/mgag200_main.c

@@ -135,10 +135,6 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags)
 		goto err_mgag200_mm_fini;
 	}
 
-	ret = mgag200_cursor_init(mdev);
-	if (ret)
-		drm_err(dev, "Could not initialize cursors. Not doing hardware cursors.\n");
-
 	return 0;
 
 err_mgag200_mm_fini:
@@ -154,7 +150,6 @@ void mgag200_driver_unload(struct drm_device *dev)
 
 	if (mdev == NULL)
 		return;
-	mgag200_cursor_fini(mdev);
 	mgag200_mm_fini(mdev);
 	dev->dev_private = NULL;
 }

drivers/gpu/drm/mgag200/mgag200_mode.c

@@ -1412,8 +1412,6 @@ static void mga_crtc_disable(struct drm_crtc *crtc)
 
 /* These provide the minimum set of functions required to handle a CRTC */
 static const struct drm_crtc_funcs mga_crtc_funcs = {
-	.cursor_set = mgag200_crtc_cursor_set,
-	.cursor_move = mgag200_crtc_cursor_move,
 	.gamma_set = mga_crtc_gamma_set,
 	.set_config = drm_crtc_helper_set_config,
 	.destroy = mga_crtc_destroy,