From bbf0cb3e93a1b6ef8bf22a67f35d7c98ef378f2b Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 26 May 2014 19:23:46 +0200 Subject: [PATCH] USB: cdc-acm: simplify runtime PM locking We can simply the runtime PM locking as there's no need to check the susp_count in the read path (at least not since killing the rx tasklet). Specifically, the read urbs will never be resubmitted by the completion handler when killed during suspend. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/cdc-acm.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 6bbd203f1861..bc7a2a6fc4ac 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -428,7 +428,7 @@ static void acm_read_bulk_callback(struct urb *urb) /* throttle device if requested by tty */ spin_lock_irqsave(&acm->read_lock, flags); acm->throttled = acm->throttle_req; - if (!acm->throttled && !acm->susp_count) { + if (!acm->throttled) { spin_unlock_irqrestore(&acm->read_lock, flags); acm_submit_read_urb(acm, rb->index, GFP_ATOMIC); } else { @@ -1546,18 +1546,15 @@ static int acm_suspend(struct usb_interface *intf, pm_message_t message) struct acm *acm = usb_get_intfdata(intf); int cnt; - spin_lock_irq(&acm->read_lock); - spin_lock(&acm->write_lock); + spin_lock_irq(&acm->write_lock); if (PMSG_IS_AUTO(message)) { if (acm->transmitting) { - spin_unlock(&acm->write_lock); - spin_unlock_irq(&acm->read_lock); + spin_unlock_irq(&acm->write_lock); return -EBUSY; } } cnt = acm->susp_count++; - spin_unlock(&acm->write_lock); - spin_unlock_irq(&acm->read_lock); + spin_unlock_irq(&acm->write_lock); if (cnt) return 0; @@ -1573,8 +1570,7 @@ static int acm_resume(struct usb_interface *intf) struct urb *urb; int rv = 0; - spin_lock_irq(&acm->read_lock); - spin_lock(&acm->write_lock); + spin_lock_irq(&acm->write_lock); if (--acm->susp_count) goto out; @@ -1600,8 +1596,7 @@ static int acm_resume(struct usb_interface *intf) rv = acm_submit_read_urbs(acm, GFP_ATOMIC); } out: - spin_unlock(&acm->write_lock); - spin_unlock_irq(&acm->read_lock); + spin_unlock_irq(&acm->write_lock); return rv; } -- 2.20.1