Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758565Ab3G0DHU (ORCPT ); Fri, 26 Jul 2013 23:07:20 -0400 Received: from mail-ob0-f171.google.com ([209.85.214.171]:42056 "EHLO mail-ob0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758512Ab3G0DHP (ORCPT ); Fri, 26 Jul 2013 23:07:15 -0400 MIME-Version: 1.0 In-Reply-To: <51F2DD90.2030405@linutronix.de> References: <1374516607-2705-1-git-send-email-bigeasy@linutronix.de> <1374516607-2705-15-git-send-email-bigeasy@linutronix.de> <51EEBE05.2040000@linutronix.de> <20130726163101.GB29819@linutronix.de> <51F2BE6F.3010008@linutronix.de> <51F2D427.7050106@linutronix.de> <51F2DD90.2030405@linutronix.de> Date: Fri, 26 Jul 2013 22:07:14 -0500 Message-ID: Subject: Re: [PATCH 14/16] usb: musb: dsps: add MUSB_DEVCTL_SESSION back after removal From: Bin Liu To: Sebastian Andrzej Siewior Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, balbi@ti.com, george.cherian@ti.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1601 Lines: 40 Sebastian, On Fri, Jul 26, 2013 at 3:35 PM, Sebastian Andrzej Siewior wrote: >> My build server is down this afternoon. Once it comes back next week, >> I will try 3.8 again, to see how I can help on this USB1 host mode >> issue. its devctl register should stay on 0x19 even nothing is >> connected. > > Your help is greatly appreciated. To hear what will happen :) > > Sebastian I have not tested it yet, but I believe I found why host mode works on TI 3.2 kernel but not on mainline. Please look at Line 786 in 3.2 kernel musb_core.c [1]. 773 if ((int_usb & MUSB_INTR_DISCONNECT) && !musb->ignore_disconnect) { ...... 785 if (musb->a_wait_bcon != 0 && 786 is_otg_enabled(musb)) 787 musb_platform_try_idle(musb, jiffies 788 + msecs_to_jiffies(musb->a_wait_bcon)); So when the device is unplugged, *_try_idle() is not called in host mode, then the SESSION bit will stay set. But in mainline kernel, *_try_idle() will be called regardless. Please let me know your thoughts. Regards, -Bin. [1] http://arago-project.org/git/projects/?p=linux-am33x.git;a=blob;f=drivers/usb/musb/musb_core.c;h=075aa5f9bec7cd041aa24eb534209fa756ed84fe;hb=refs/heads/v3.2-staging -- 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/