Revert "drm: cleanup: drm_modeset_lock_all_ctx() --> DRM_MODESET_LOCK_ALL_BEGIN()"

This reverts commit 21dde409.

This patchset breaks on intel platforms and was previously NACK'd by
Ville.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Fernando Ramos <greenfoo@u92.eu>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211002154542.15800-16-sean@poorly.run

drivers/gpu/drm/drm_client_modeset.c

@@ -574,7 +574,6 @@ static bool drm_client_firmware_config(struct drm_client_dev *client,
 	int num_connectors_detected = 0;
 	int num_tiled_conns = 0;
 	struct drm_modeset_acquire_ctx ctx;
-	int err;
 
 	if (!drm_drv_uses_atomic_modeset(dev))
 		return false;
@@ -586,7 +585,10 @@ static bool drm_client_firmware_config(struct drm_client_dev *client,
 	if (!save_enabled)
 		return false;
 
-	DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, 0, err);
+	drm_modeset_acquire_init(&ctx, 0);
+
+	while (drm_modeset_lock_all_ctx(dev, &ctx) != 0)
+		drm_modeset_backoff(&ctx);
 
 	memcpy(save_enabled, enabled, count);
 	mask = GENMASK(count - 1, 0);
@@ -741,7 +743,8 @@ static bool drm_client_firmware_config(struct drm_client_dev *client,
 		ret = false;
 	}
 
-	DRM_MODESET_LOCK_ALL_END(dev, ctx, err);
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
 
 	kfree(save_enabled);
 	return ret;