Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934168AbaKMUlq (ORCPT ); Thu, 13 Nov 2014 15:41:46 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:42556 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S932767AbaKMUlo (ORCPT ); Thu, 13 Nov 2014 15:41:44 -0500 Date: Thu, 13 Nov 2014 15:41:43 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Benson Leung cc: johan@kernel.org, , , , , Subject: Re: [PATCH] HID: usbhid: get/put around clearing needs_remote_wakeup In-Reply-To: <1415909806-23848-1-git-send-email-bleung@chromium.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 13 Nov 2014, Benson Leung wrote: > usbhid->intf->needs_remote_wakeup is set when a device is > opened, and is cleared when a device is closed. > > When a usbhid device that does not support remote wake > ( i.e. !device_can_wakeup() ) is closed, we fail out of > autosuspend_check() because the autosuspend check is called > before the flag is cleared as a result of usb_kill_urb(usbhid->urbin); > > The result is that a device that may otherwise autosuspend will > fail to enter suspend again after all handles to it are closed. > > In usbhid_open, usb_autopm_get_interface is called > before setting the needs_remote_wakeup flag, and > usb_autopm_put_interface is called after hid_start_in. > > However, when the device is closed in usbhid_close, the same > protection isn't there when clearing needs_remote_wakeup. This will > add that to usbhid_close as well as usbhid_stop. usbhid_stop probably doesn't need it. And it should be possible to fix usbhid_close more easily just by interchanging the two lines: - usb_kill_urb(usbhid->urbin); usbhid->intf->needs_remote_wakeup = 0; + usb_kill_urb(usbhid->urbin); Have you tried this? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/