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HID: fix tty<->hid deadlock

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hid_compat_load() runs on the default workqueue, it request_module(), it
execs modprobe, it exits, tty flushes default workqueue, it hangs, because
we are still in it.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Tested-by: <Valdis.Kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Jiri Slaby
2008-09-09 01:23:03 +02:00
committed by Jiri Kosina
parent d1d3a5f6ea
commit d92870ddd2
1 changed files with 10 additions and 1 deletions
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11
drivers/hid/hid-core.c
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@@ -1657,6 +1657,7 @@ static void hid_compat_load(struct work_struct *ws)
request_module("hid-dummy"); request_module("hid-dummy");
} }
static DECLARE_WORK(hid_compat_work, hid_compat_load); static DECLARE_WORK(hid_compat_work, hid_compat_load);
static struct workqueue_struct *hid_compat_wq;
#endif #endif
static int __init hid_init(void) static int __init hid_init(void)
@@ -1674,7 +1675,12 @@ static int __init hid_init(void)
goto err_bus; goto err_bus;
#ifdef CONFIG_HID_COMPAT #ifdef CONFIG_HID_COMPAT
schedule_work(&hid_compat_work); hid_compat_wq = create_workqueue("hid_compat");
if (!hid_compat_wq) {
hidraw_exit();
goto err;
}
queue_work(hid_compat_wq, &hid_compat_work);
#endif #endif
return 0; return 0;
@@ -1686,6 +1692,9 @@ err:
static void __exit hid_exit(void) static void __exit hid_exit(void)
{ {
#ifdef CONFIG_HID_COMPAT
destroy_workqueue(hid_compat_wq);
#endif
hidraw_exit(); hidraw_exit();
bus_unregister(&hid_bus_type); bus_unregister(&hid_bus_type);
} }