drm/qxl: Run DRM default client setup

Call drm_client_setup() to run the kernel's default client setup
for DRM. Set fbdev_probe in struct drm_driver, so that the client
setup can start the common fbdev client.

The qxl driver specifies a preferred color mode of 32. As this
is the default if no format has been given, leave it out entirely.

v5:
- select DRM_CLIENT_SELECTION

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240924071734.98201-70-tzimmermann@suse.de

drivers/gpu/drm/qxl/Kconfig

@@ -2,6 +2,7 @@
 config DRM_QXL
 	tristate "QXL virtual GPU"
 	depends on DRM && PCI && MMU
+	select DRM_CLIENT_SELECTION
 	select DRM_KMS_HELPER
 	select DRM_TTM
 	select DRM_TTM_HELPER

drivers/gpu/drm/qxl/qxl_drv.c

@@ -36,6 +36,7 @@
 #include <drm/drm.h>
 #include <drm/drm_aperture.h>
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_client_setup.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_fbdev_ttm.h>
 #include <drm/drm_file.h>
@@ -118,7 +119,7 @@ qxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (ret)
 		goto modeset_cleanup;
 
-	drm_fbdev_ttm_setup(&qdev->ddev, 32);
+	drm_client_setup(&qdev->ddev, NULL);
 	return 0;
 
 modeset_cleanup:
@@ -293,6 +294,7 @@ static struct drm_driver qxl_driver = {
 	.debugfs_init = qxl_debugfs_init,
 #endif
 	.gem_prime_import_sg_table = qxl_gem_prime_import_sg_table,
+	DRM_FBDEV_TTM_DRIVER_OPS,
 	.fops = &qxl_fops,
 	.ioctls = qxl_ioctls,
 	.num_ioctls = ARRAY_SIZE(qxl_ioctls),