Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755113AbaLVQGX (ORCPT ); Mon, 22 Dec 2014 11:06:23 -0500 Received: from netrider.rowland.org ([192.131.102.5]:34128 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754588AbaLVQGW (ORCPT ); Mon, 22 Dec 2014 11:06:22 -0500 Date: Mon, 22 Dec 2014 11:06:20 -0500 (EST) From: Alan Stern X-X-Sender: stern@netrider.rowland.org To: Wu Liang feng cc: heiko@sntech.de, , , , , , , , , , , Subject: Re: [PATCH 2/2] USB: ehci-platform: Support ehci reset after resume quirk In-Reply-To: <1419244588-5227-3-git-send-email-wulf@rock-chips.com> 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 Mon, 22 Dec 2014, Wu Liang feng wrote: > The EHCI controller doesn't properly detect the case when "The" EHCI controller? I don't know what EHCI controller you're talking about, but my controllers don't have any trouble detecting device removal during suspend. > a device is removed during suspend. Specifically,when we > resume from suspend the EHCI controller maintaining the > USB state (FLAG_CF is 1 Current Connect Status is 1) but > a USB device (like a USB camera on rk3288) may have been > disconnected actually. > > Let's add a quirk to force ehci to go into the > usb_root_hub_lost_power() path and reset after resume. > This should generally reset the whole controller and all > ports and initialize everything cleanly again, and bring > the devices back up. Isn't this solution too extreme? What if the device was a flash storage drive and it wasn't unplugged during suspend? This patch would force it to be removed, messing up any mounted filesystems, when there was no need. Can you find a better way to work around the problem? 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/