From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: [patch V3 03/20] usb: gadget: Use completion interface instead of open coding it Date: Sat, 21 Mar 2020 12:25:47 +0100 Message-ID: <20200321113241.043380271@linutronix.de> References: <20200321112544.878032781@linutronix.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8-bit Return-path: Sender: linux-pci-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: LKML Cc: Peter Zijlstra , Ingo Molnar , Sebastian Siewior , Linus Torvalds , Joel Fernandes , Oleg Nesterov , Davidlohr Bueso , Greg Kroah-Hartman , Felipe Balbi , linux-usb@vger.kernel.org, Logan Gunthorpe , Bjorn Helgaas , Kurt Schwemmer , linux-pci@vger.kernel.org, Kalle Valo , "David S. Miller" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, Darren Hart , Andy Shevchenko , platform-driver-x86@vg From: Thomas Gleixner ep_io() uses a completion on stack and open codes the waiting with: wait_event_interruptible (done.wait, done.done); and wait_event (done.wait, done.done); This waits in non-exclusive mode for complete(), but there is no reason to do so because the completion can only be waited for by the task itself and complete() wakes exactly one exlusive waiter. Replace the open coded implementation with the corresponding wait_for_completion*() functions. No functional change. Reported-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Reviewed-by: Greg Kroah-Hartman Cc: Felipe Balbi Cc: linux-usb@vger.kernel.org --- V2: New patch to avoid the conversion to swait interfaces later --- drivers/usb/gadget/legacy/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -344,7 +344,7 @@ ep_io (struct ep_data *epdata, void *buf spin_unlock_irq (&epdata->dev->lock); if (likely (value == 0)) { - value = wait_event_interruptible (done.wait, done.done); + value = wait_for_completion_interruptible(&done); if (value != 0) { spin_lock_irq (&epdata->dev->lock); if (likely (epdata->ep != NULL)) { @@ -353,7 +353,7 @@ ep_io (struct ep_data *epdata, void *buf usb_ep_dequeue (epdata->ep, epdata->req); spin_unlock_irq (&epdata->dev->lock); - wait_event (done.wait, done.done); + wait_for_completion(&done); if (epdata->status == -ECONNRESET) epdata->status = -EINTR; } else {