From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162190Ab3LFNTI (ORCPT ); Fri, 6 Dec 2013 08:19:08 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:44607 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161941Ab3LFNE3 (ORCPT ); Fri, 6 Dec 2013 08:04:29 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Daniel Mack , Sebastian Andrzej Siewior , Felipe Balbi , Luis Henriques Subject: [PATCH 3.11 221/272] usb: musb: call musb_start() only once in OTG mode Date: Fri, 6 Dec 2013 12:58:30 +0000 Message-Id: <1386334761-25517-222-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1386334761-25517-1-git-send-email-luis.henriques@canonical.com> References: <1386334761-25517-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior commit ae44df2e21b50f9fff28ac75c57e399c04df812c upstream. In commit 001dd84 ("usb: musb: start musb on the udc side, too") it was ensured that the state engine is started also in OTG mode after a removal / insertion of the gadget. Unfortunately this change also introduced a bug: If the device is configured as OTG and it connected with a remote host _without_ loading a gadget then we bug() later (because musb->otg->gadget is not initialized). Initially I assumed it might be nice to have the host part of musb in OTG mode working without having a gadget loaded. This bug and fact that it wasn't working like this before the host/gadget split made me realize that this was a silly idea. This patch now introduces back the old behavior where in OTG mode the host mode is only working after the gadget has been loaded. Cc: Daniel Mack Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Felipe Balbi Signed-off-by: Luis Henriques --- drivers/usb/musb/musb_virthub.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/drivers/usb/musb/musb_virthub.c b/drivers/usb/musb/musb_virthub.c index d1d6b83..9af6bba 100644 --- a/drivers/usb/musb/musb_virthub.c +++ b/drivers/usb/musb/musb_virthub.c @@ -220,6 +220,23 @@ int musb_hub_status_data(struct usb_hcd *hcd, char *buf) return retval; } +static int musb_has_gadget(struct musb *musb) +{ + /* + * In host-only mode we start a connection right away. In OTG mode + * we have to wait until we loaded a gadget. We don't really need a + * gadget if we operate as a host but we should not start a session + * as a device without a gadget or else we explode. + */ +#ifdef CONFIG_USB_MUSB_HOST + return 1; +#else + if (musb->port_mode == MUSB_PORT_MODE_HOST) + return 1; + return musb->g.dev.driver != NULL; +#endif +} + int musb_hub_control( struct usb_hcd *hcd, u16 typeReq, @@ -362,7 +379,7 @@ int musb_hub_control( * initialization logic, e.g. for OTG, or change any * logic relating to VBUS power-up. */ - if (!hcd->self.is_b_host) + if (!hcd->self.is_b_host && musb_has_gadget(musb)) musb_start(musb); break; case USB_PORT_FEAT_RESET: -- 1.8.3.2