diff options
| author | Jon Povey <jon.povey@racelogic.co.uk> | 2010-06-14 19:41:04 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-02 10:29:58 -0700 |
| commit | 54fb947936efde2d9710f3d3748755f36a381ac9 (patch) | |
| tree | 1db3ba6f3df93e4b8271198afa1d75b41e384d6c /drivers | |
| parent | c226e63e40f2d3caa0ecd056c35c2e17332eac68 (diff) | |
| download | lwn-54fb947936efde2d9710f3d3748755f36a381ac9.tar.gz lwn-54fb947936efde2d9710f3d3748755f36a381ac9.zip | |
USB: g_serial: don't set low_latency flag
commit 44a0c0190b500ee6bcfc0976fe540f65dee2cd67 upstream.
No longer set low_latency flag as it causes this warning backtrace:
WARNING: at kernel/mutex.c:207 __mutex_lock_slowpath+0x6c/0x288()
Fix associated locking and wakeups.
Signed-off-by: Jon Povey <jon.povey@racelogic.co.uk>
Cc: Maulik Mankad <x0082077@ti.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/gadget/u_serial.c | 15 |
1 files changed, 2 insertions, 13 deletions
diff --git a/drivers/usb/gadget/u_serial.c b/drivers/usb/gadget/u_serial.c index 16bdf77f582a..a0f79df4c6c2 100644 --- a/drivers/usb/gadget/u_serial.c +++ b/drivers/usb/gadget/u_serial.c @@ -536,17 +536,11 @@ recycle: list_move(&req->list, &port->read_pool); } - /* Push from tty to ldisc; this is immediate with low_latency, and - * may trigger callbacks to this driver ... so drop the spinlock. + /* Push from tty to ldisc; without low_latency set this is handled by + * a workqueue, so we won't get callbacks and can hold port_lock */ if (tty && do_push) { - spin_unlock_irq(&port->port_lock); tty_flip_buffer_push(tty); - wake_up_interruptible(&tty->read_wait); - spin_lock_irq(&port->port_lock); - - /* tty may have been closed */ - tty = port->port_tty; } @@ -784,11 +778,6 @@ static int gs_open(struct tty_struct *tty, struct file *file) port->open_count = 1; port->openclose = false; - /* low_latency means ldiscs work in tasklet context, without - * needing a workqueue schedule ... easier to keep up. - */ - tty->low_latency = 1; - /* if connected, start the I/O stream */ if (port->port_usb) { struct gserial *gser = port->port_usb; |