From 7e50e0bec45897caeb978e5aecc9184a2dc00df2 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Thu, 17 Oct 2013 19:19:04 +0200 Subject: [PATCH] uas: Avoid unnecessary unlock / lock calls around unlink_data_urbs All callers of unlink_data_urbs drop devinfo->lock before calling it, and then immediately take it again after the call. And the first thing unlink_data_urbs does is take the lock again, and the last thing it does is drop it. This commit removes all the unnecessary lock dropping and taking. Signed-off-by: Hans de Goede Signed-off-by: Sarah Sharp --- drivers/usb/storage/uas.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c index ec1b22d29501..dcaf61197032 100644 --- a/drivers/usb/storage/uas.c +++ b/drivers/usb/storage/uas.c @@ -93,28 +93,26 @@ static void uas_configure_endpoints(struct uas_dev_info *devinfo); static void uas_free_streams(struct uas_dev_info *devinfo); static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *caller); +/* Must be called with devinfo->lock held, will temporary unlock the lock */ static void uas_unlink_data_urbs(struct uas_dev_info *devinfo, - struct uas_cmd_info *cmdinfo) + struct uas_cmd_info *cmdinfo, + unsigned long *lock_flags) { - unsigned long flags; - /* * The UNLINK_DATA_URBS flag makes sure uas_try_complete * (called by urb completion) doesn't release cmdinfo * underneath us. */ - spin_lock_irqsave(&devinfo->lock, flags); cmdinfo->state |= UNLINK_DATA_URBS; - spin_unlock_irqrestore(&devinfo->lock, flags); + spin_unlock_irqrestore(&devinfo->lock, *lock_flags); if (cmdinfo->data_in_urb) usb_unlink_urb(cmdinfo->data_in_urb); if (cmdinfo->data_out_urb) usb_unlink_urb(cmdinfo->data_out_urb); - spin_lock_irqsave(&devinfo->lock, flags); + spin_lock_irqsave(&devinfo->lock, *lock_flags); cmdinfo->state &= ~UNLINK_DATA_URBS; - spin_unlock_irqrestore(&devinfo->lock, flags); } static void uas_do_work(struct work_struct *work) @@ -361,9 +359,7 @@ static void uas_stat_cmplt(struct urb *urb) uas_sense(urb, cmnd); if (cmnd->result != 0) { /* cancel data transfers on error */ - spin_unlock_irqrestore(&devinfo->lock, flags); - uas_unlink_data_urbs(devinfo, cmdinfo); - spin_lock_irqsave(&devinfo->lock, flags); + uas_unlink_data_urbs(devinfo, cmdinfo, &flags); } cmdinfo->state &= ~COMMAND_INFLIGHT; uas_try_complete(cmnd, __func__); @@ -787,9 +783,7 @@ static int uas_eh_abort_handler(struct scsi_cmnd *cmnd) spin_unlock_irqrestore(&devinfo->lock, flags); ret = uas_eh_task_mgmt(cmnd, "ABORT TASK", TMF_ABORT_TASK); } else { - spin_unlock_irqrestore(&devinfo->lock, flags); - uas_unlink_data_urbs(devinfo, cmdinfo); - spin_lock_irqsave(&devinfo->lock, flags); + uas_unlink_data_urbs(devinfo, cmdinfo, &flags); uas_try_complete(cmnd, __func__); spin_unlock_irqrestore(&devinfo->lock, flags); ret = SUCCESS; -- 2.30.2