[PATCH 1/4] HID: picolcd: fix deferred_io init/cleanup to(un)register_framebuffer ordering

[Bruno PrÃmont]

We need to call fb_deferred_io_init() before we register_framebuffer()
as otherwise, in case fbcon uses our framebuffer, we will get a BUG()
because in picolcd_fb_imageblit() we schedule defio which has not
been initialized yet.

Note: this BUG() deadlocks ttys.

Signed-off-by: Bruno PrÃmont <bonbons@xxxxxxxxxxxxxxxxx>
---
 drivers/hid/hid-picolcd.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-picolcd.c b/drivers/hid/hid-picolcd.c
index 95253b3..883d720 100644
--- a/drivers/hid/hid-picolcd.c
+++ b/drivers/hid/hid-picolcd.c
@@ -707,18 +707,19 @@ static int picolcd_init_framebuffer(struct picolcd_data *data)
 		dev_err(dev, "failed to create sysfs attributes\n");
 		goto err_cleanup;
 	}
+	fb_deferred_io_init(info);
 	data->fb_info    = info;
 	error = register_framebuffer(info);
 	if (error) {
 		dev_err(dev, "failed to register framebuffer\n");
 		goto err_sysfs;
 	}
-	fb_deferred_io_init(info);
 	/* schedule first output of framebuffer */
 	schedule_delayed_work(&info->deferred_work, 0);
 	return 0;
 
 err_sysfs:
+	fb_deferred_io_cleanup(info);
 	device_remove_file(dev, &dev_attr_fb_update_rate);
 err_cleanup:
 	data->fb_vbitmap = NULL;
@@ -747,7 +748,6 @@ static void picolcd_exit_framebuffer(struct picolcd_data *data)
 	data->fb_bpp     = 0;
 	data->fb_info    = NULL;
 	device_remove_file(&data->hdev->dev, &dev_attr_fb_update_rate);
-	fb_deferred_io_cleanup(info);
 	unregister_framebuffer(info);
 	vfree(fb_bitmap);
 	kfree(fb_vbitmap);
-- 
1.7.1

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