From stern@rowland.harvard.edu Fri Aug 24 12:42:44 2007 From: Alan Stern Date: Fri, 24 Aug 2007 15:42:39 -0400 (EDT) Subject: USB: get rid of urb->lock To: Greg KH Cc: USB development list Message-ID: Now that urb->status isn't used, urb->lock doesn't protect anything. This patch (as980) removes it and replaces it with a private mutex in the one remaining place it was still used: usb_kill_urb. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/urb.c | 11 ++++++----- include/linux/usb.h | 4 ---- 2 files changed, 6 insertions(+), 9 deletions(-) --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -39,7 +39,6 @@ void usb_init_urb(struct urb *urb) if (urb) { memset(urb, 0, sizeof(*urb)); kref_init(&urb->kref); - spin_lock_init(&urb->lock); INIT_LIST_HEAD(&urb->anchor_list); } } @@ -541,19 +540,21 @@ int usb_unlink_urb(struct urb *urb) */ void usb_kill_urb(struct urb *urb) { + static DEFINE_MUTEX(reject_mutex); + might_sleep(); if (!(urb && urb->dev && urb->ep)) return; - spin_lock_irq(&urb->lock); + mutex_lock(&reject_mutex); ++urb->reject; - spin_unlock_irq(&urb->lock); + mutex_unlock(&reject_mutex); usb_hcd_unlink_urb(urb, -ENOENT); wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); - spin_lock_irq(&urb->lock); + mutex_lock(&reject_mutex); --urb->reject; - spin_unlock_irq(&urb->lock); + mutex_unlock(&reject_mutex); } /** --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1241,7 +1241,6 @@ struct urb { /* private: usb core and host controller only fields in the urb */ struct kref kref; /* reference count of the URB */ - spinlock_t lock; /* lock for the URB */ void *hcpriv; /* private data for host controller */ atomic_t use_count; /* concurrent submissions counter */ u8 reject; /* submissions will fail */ @@ -1299,7 +1298,6 @@ static inline void usb_fill_control_urb usb_complete_t complete_fn, void *context) { - spin_lock_init(&urb->lock); urb->dev = dev; urb->pipe = pipe; urb->setup_packet = setup_packet; @@ -1330,7 +1328,6 @@ static inline void usb_fill_bulk_urb (st usb_complete_t complete_fn, void *context) { - spin_lock_init(&urb->lock); urb->dev = dev; urb->pipe = pipe; urb->transfer_buffer = transfer_buffer; @@ -1366,7 +1363,6 @@ static inline void usb_fill_int_urb (str void *context, int interval) { - spin_lock_init(&urb->lock); urb->dev = dev; urb->pipe = pipe; urb->transfer_buffer = transfer_buffer;