| Message ID | 20200318204407.700914073@linutronix.de (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | Lock ordering documentation and annotation for lockdep | expand |
On Wed, Mar 18, 2020 at 09:43:05PM +0100, Thomas Gleixner wrote: > 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 <bigeasy@linutronix.de> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Cc: Felipe Balbi <balbi@kernel.org> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: linux-usb@vger.kernel.org > --- > V2: New patch to avoid the conversion to swait interfaces later > --- Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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 {
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 <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Felipe Balbi <balbi@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 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(-)