From patchwork Tue Mar 28 06:10:00 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Moreno Bartalucci X-Patchwork-Id: 9648181 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 91FC2602C8 for ; Tue, 28 Mar 2017 06:10:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 74A7A2839B for ; Tue, 28 Mar 2017 06:10:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 55528283FF; Tue, 28 Mar 2017 06:10:49 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3CEE72839B for ; Tue, 28 Mar 2017 06:10:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753612AbdC1GKY convert rfc822-to-8bit (ORCPT ); Tue, 28 Mar 2017 02:10:24 -0400 Received: from out.consiagnet.it ([83.149.128.196]:47479 "EHLO out.consiagnet.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752760AbdC1GKX (ORCPT ); Tue, 28 Mar 2017 02:10:23 -0400 Received: from hermes.tecnorama.it (host-static-157-154.consiagnet.it [83.149.157.154] (may be forged)) by out.consiagnet.it (8.15.2/8.15.2) with ESMTP id v2S6A8M1078578; Tue, 28 Mar 2017 08:10:08 +0200 (CEST) (envelope-from moreno.bartalucci@tecnorama.it) Received: from localhost (localhost [127.0.0.1]) by hermes.tecnorama.it (Postfix) with ESMTP id 8E86CB40559; Tue, 28 Mar 2017 08:09:52 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at tecnorama.it Received: from hermes.tecnorama.it ([127.0.0.1]) by localhost (hermes.tecnorama.it [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id M0YHJdmc1rX2; Tue, 28 Mar 2017 08:09:50 +0200 (CEST) Received: from macmoreno.tecnorama.it (macmoreno.tecnorama.it [192.168.100.21]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by hermes.tecnorama.it (Postfix) with ESMTPSA id 61FEBB40438; Tue, 28 Mar 2017 08:09:50 +0200 (CEST) Mime-Version: 1.0 (Mac OS X Mail 10.2 \(3259\)) Subject: Re: [PATCH] usb-musb: keep VBUS on when device is disconnected From: Moreno Bartalucci In-Reply-To: <20170327171534.GA4403@uda0271908> Date: Tue, 28 Mar 2017 08:10:00 +0200 Cc: Tony Lindgren , Lars Melin , "linux-omap@vger.kernel.org" , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Alessio Igor Bogani Message-Id: <11BBAEC7-0B26-40FE-963E-811F7853F2FE@tecnorama.it> References: <20170315140801.97230-1-moreno.bartalucci@tecnorama.it> <20170324185836.GC19814@uda0271908> <2d10809f-d482-ffa9-30b7-8785e94ab102@gmail.com> <00882633-3F61-4010-A4D2-D04473282B10@tecnorama.it> <20170327131701.GA12674@uda0271908> <20170327143049.GG10760@atomide.com> <63FD9E13-2B70-485C-80A7-206BEC16905A@tecnorama.it> <20170327165946.GL10760@atomide.com> <20170327171534.GA4403@uda0271908> To: Bin Liu X-Mailer: Apple Mail (2.3259) Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP > Il giorno 27 mar 2017, alle ore 19:15, Bin Liu ha scritto: > > […] > > The MUSB otg state machine has been changed in many place since the last > time I looked at it, and I am not sure how exactly it works now. > > If the $subject patch can correctly keep the VBUS on for host-only mode, > we can somehow use dr_modei value to distinguish the mode. We don't have > to create a new vbus-always-on-in-host-mode flag. VBUS has to be always > on in host-only mode anyway, until some error condition happens. > During my research, I used this patch to try to print the status of the usb port: Unless I did something wrong, maybe it’s worth to notice that before the patch that apparently introduced this bug (2f3fd2c5bde1f94513c3dc311ae64494085ec371) I got nothing printed anywhere. With that patch applied, instead, I got the line printed in dmesg. I might be wrong but my assumption is that without that patch otg_timer was never called. If this is true, it would explain why writing 0 on DEVCTL didn’t bother anything: it never happened. Regards, Moreno --- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- a/drivers/usb/musb/musb_dsps.c 2017-03-13 09:34:31.000000000 +0100 +++ b/drivers/usb/musb/musb_dsps.c 2017-03-13 09:36:02.000000000 +0100 @@ -245,6 +245,8 @@ static void otg_timer(unsigned long _mus dev_dbg(musb->controller, "Poll devctl %02x (%s)\n", devctl, usb_otg_state_string(musb->xceiv->otg->state)); + dev_emerg(musb->controller, "musb->xceiv->otg->state=%s, musb->port_mode=%d\n", usb_otg_state_string(musb->xceiv->otg->state),(int)musb->port_mode); + spin_lock_irqsave(&musb->lock, flags); switch (musb->xceiv->otg->state) { case OTG_STATE_A_WAIT_BCON: