Date: Wed, 11 Nov 2015 16:28:16 -0700
From: Pete Zaitcev <zaitcev@redhat.com>
To: Jiri Slaby <jslaby@suse.cz>
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>, zaitcev@redhat.com
Subject: Re: [PATCH 1/1] usblp: do not set TASK_INTERRUPTIBLE before lock
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On Mon,  2 Nov 2015 10:27:00 +0100
Jiri Slaby <jslaby@suse.cz> wrote:

> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> --- a/drivers/usb/class/usblp.c
> +++ b/drivers/usb/class/usblp.c
> @@ -884,11 +884,11 @@ static int usblp_wwait(struct usblp *usblp, int nonblock)
>  
>  	add_wait_queue(&usblp->wwait, &waita);
>  	for (;;) {
> -		set_current_state(TASK_INTERRUPTIBLE);
>  		if (mutex_lock_interruptible(&usblp->mut)) {
>  			rc = -EINTR;
>  			break;
>  		}
> +		set_current_state(TASK_INTERRUPTIBLE);
>  		rc = usblp_wtest(usblp, nonblock);
>  		mutex_unlock(&usblp->mut);
>  		if (rc <= 0)

I'm fully onboard with this. In the original "big cleanup" 317c67b8f,
I got this right. But then I either missed that mutex_lock_interruptible()
can set the state, or it didn't do it back then (it was in 2007), and
the 7f477358e introduced the existing code.

Acked-By: Pete Zaitcev <zaitcev@yahoo.com>

-- Pete
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