drm/fb-helper: Remove drm_fb_helper_crtc

struct drm_fb_helper_crtc is now just a wrapper around drm_mode_set so
use that directly instead and attach it as a modeset array onto
drm_client_dev. drm_fb_helper will use this array to store its modesets
which means it will always initialize a drm_client, but it will not
register the client (callbacks) unless it's the generic fbdev emulation.

Code will later be moved to drm_client, so add code there in a new file
drm_client_modeset.c with MIT license to match drm_fb_helper.c.

The modeset connector array size is hardcoded for the cloned case to avoid
having to pass in a value from the driver. A value of 8 is chosen to err
on the safe side. This means that the max connector argument for
drm_fb_helper_init() and drm_fb_helper_fbdev_setup() isn't used anymore,
a todo entry for this is added.

In pan_display_atomic() restore_fbdev_mode_force() is used instead of
restore_fbdev_mode_atomic() because that one will later become internal
to drm_client_modeset.

Locking order:
1. drm_fb_helper->lock
2. drm_master_internal_acquire
3. drm_client_dev->modeset_mutex

v6: Improve commit message (Sam Ravnborg)

v3:
- Use full drm_client_init/release for the modesets (Daniel Vetter)
- drm_client_for_each_modeset: use lockdep_assert_held (Daniel Vetter)
- Hook up to Documentation/gpu/drm-client.rst (Daniel Vetter)

v2:
- Add modesets array to drm_client (Daniel Vetter)
- Use a new file for the modeset code (Daniel Vetter)
- File has to be MIT licensed (Emmanuel Vadot)
- Add copyrights from drm_fb_helper.c

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190531140117.37751-3-noralf@tronnes.org

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index e7870a54f498..410572f14257 100644
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -27,7 +27,6 @@
  * DOC: overview
  *
  * This library provides support for clients running in the kernel like fbdev and bootsplash.
- * Currently it's only partially implemented, just enough to support fbdev.
  *
  * GEM drivers which provide a GEM based dumb buffer with a virtual address are supported.
  */
@@ -92,14 +91,20 @@ int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,
 	client->name = name;
 	client->funcs = funcs;
 
-	ret = drm_client_open(client);
+	ret = drm_client_modeset_create(client);
 	if (ret)
 		goto err_put_module;
 
+	ret = drm_client_open(client);
+	if (ret)
+		goto err_free;
+
 	drm_dev_get(dev);
 
 	return 0;
 
+err_free:
+	drm_client_modeset_free(client);
 err_put_module:
 	if (funcs)
 		module_put(funcs->owner);
@@ -148,6 +153,7 @@ void drm_client_release(struct drm_client_dev *client)
 
 	DRM_DEV_DEBUG_KMS(dev->dev, "%s\n", client->name);
 
+	drm_client_modeset_free(client);
 	drm_client_close(client);
 	drm_dev_put(dev);
 	if (client->funcs)