diff options
| author | Johan Hovold <johan@kernel.org> | 2019-04-25 18:05:40 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-29 16:14:41 +0200 |
| commit | 0f02321e4bd1b17eb957e077e868ef1611f5dbbd (patch) | |
| tree | a4231114463fce1f3822a289fbd339b0520825ce /drivers/usb/class/cdc-acm.c | |
| parent | 764478f41130f1b8d8057575b89e69980a0f600d (diff) | |
USB: cdc-acm: clean up throttle handling
Clean up the throttle implementation by dropping the redundant
throttle_req flag which was a remnant from back when USB serial had only
a single read URB, something which was later carried over to cdc-acm.
Also convert the throttled flag to an atomic bit flag.
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/class/cdc-acm.c')
| -rw-r--r-- | drivers/usb/class/cdc-acm.c | 33 |
1 files changed, 8 insertions, 25 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index c03aa8550980..183b41753c98 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -468,7 +468,6 @@ static void acm_read_bulk_callback(struct urb *urb) { struct acm_rb *rb = urb->context; struct acm *acm = rb->instance; - unsigned long flags; int status = urb->status; bool stopped = false; bool stalled = false; @@ -525,15 +524,10 @@ static void acm_read_bulk_callback(struct urb *urb) return; } - /* throttle device if requested by tty */ - spin_lock_irqsave(&acm->read_lock, flags); - acm->throttled = acm->throttle_req; - if (!acm->throttled) { - spin_unlock_irqrestore(&acm->read_lock, flags); - acm_submit_read_urb(acm, rb->index, GFP_ATOMIC); - } else { - spin_unlock_irqrestore(&acm->read_lock, flags); - } + if (test_bit(ACM_THROTTLED, &acm->flags)) + return; + + acm_submit_read_urb(acm, rb->index, GFP_ATOMIC); } /* data interface wrote those outgoing bytes */ @@ -670,10 +664,7 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty) /* * Unthrottle device in case the TTY was closed while throttled. */ - spin_lock_irq(&acm->read_lock); - acm->throttled = 0; - acm->throttle_req = 0; - spin_unlock_irq(&acm->read_lock); + clear_bit(ACM_THROTTLED, &acm->flags); retval = acm_submit_read_urbs(acm, GFP_KERNEL); if (retval) @@ -841,27 +832,19 @@ static void acm_tty_throttle(struct tty_struct *tty) { struct acm *acm = tty->driver_data; - spin_lock_irq(&acm->read_lock); - acm->throttle_req = 1; - spin_unlock_irq(&acm->read_lock); + set_bit(ACM_THROTTLED, &acm->flags); } static void acm_tty_unthrottle(struct tty_struct *tty) { struct acm *acm = tty->driver_data; - unsigned int was_throttled; - spin_lock_irq(&acm->read_lock); - was_throttled = acm->throttled; - acm->throttled = 0; - acm->throttle_req = 0; - spin_unlock_irq(&acm->read_lock); + clear_bit(ACM_THROTTLED, &acm->flags); /* Matches the smp_mb__after_atomic() in acm_read_bulk_callback(). */ smp_mb(); - if (was_throttled) - acm_submit_read_urbs(acm, GFP_KERNEL); + acm_submit_read_urbs(acm, GFP_KERNEL); } static int acm_tty_break_ctl(struct tty_struct *tty, int state) |