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

From: Bruno PrÃmont
Date: Mon Jun 28 2010 - 16:35:34 EST


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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