From mboxrd@z Thu Jan 1 00:00:00 1970 From: vichy Subject: Re: Auto suspend not working on usb hid devices Date: Mon, 12 Jan 2015 20:45:23 +0800 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Received: from mail-ob0-f176.google.com ([209.85.214.176]:51012 "EHLO mail-ob0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751039AbbALMpY (ORCPT ); Mon, 12 Jan 2015 07:45:24 -0500 Received: by mail-ob0-f176.google.com with SMTP id vb8so22014640obc.7 for ; Mon, 12 Jan 2015 04:45:24 -0800 (PST) In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Alan Stern Cc: linux-pm@vger.kernel.org hi alan: > I found the power/runtime_usage = 2 when device plug in and do nothing. > Except update_autosuspend will increase runtime_usage, is there any > function will increase it when we did not enable runtime > suspend/resume? We found the runtime_usage will be 2 after calling usb_new_device. in usb_new_device, pm_runtime_set_active(&udev->dev); pm_runtime_get_noresume(&udev->dev); // after calling left function, runtime_usage =1 pm_runtime_use_autosuspend(&udev->dev); pm_runtime_enable(&udev->dev); /* By default, forbid autosuspend for all devices. It will be * allowed for hubs during binding. */ usb_disable_autosuspend(udev); // after calling left function, runtime_usage =2 Under what circumstance, the runtime_usage will be 1 to let "echo auto > power/control" work? appreciate your kind help,