Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757761AbbKSGsk (ORCPT ); Thu, 19 Nov 2015 01:48:40 -0500 Received: from mail-yk0-f175.google.com ([209.85.160.175]:33405 "EHLO mail-yk0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753065AbbKSGsi (ORCPT ); Thu, 19 Nov 2015 01:48:38 -0500 MIME-Version: 1.0 In-Reply-To: <564C9A22.2060102@hurleysoftware.com> References: <564C9A22.2060102@hurleysoftware.com> Date: Thu, 19 Nov 2015 14:48:38 +0800 Message-ID: Subject: Re: [PATCH] usb: gadget: Add the console support for usb-to-serial port From: Baolin Wang To: Peter Hurley Cc: Felipe Balbi , Greg KH , r.baldyga@samsung.com, fabio.estevam@freescale.com, Philip Oberstaller , scottwood@freescale.com, Mark Brown , USB , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1761 Lines: 54 > >> +{ >> + struct gscons_info *info = gserial_cons.data; >> + int port_num = gserial_cons.index; >> + struct usb_request *req; >> + struct gs_port *port; >> + struct usb_ep *ep; >> + >> + if (port_num >= MAX_U_SERIAL_PORTS || port_num < 0) { >> + pr_err("%s: port num [%d] exceeds the range.\n", >> + __func__, port_num); >> + return -ENXIO; >> + } >> + >> + port = ports[port_num].port; >> + if (!port) { >> + pr_err("%s: serial line [%d] not allocated.\n", >> + __func__, port_num); >> + return -ENODEV; >> + } >> + >> + if (!port->port_usb) { >> + pr_err("%s: no port usb.\n", __func__); >> + return -ENODEV; >> + } >> + >> + ep = port->port_usb->in; >> + if (!ep) { >> + pr_err("%s: no usb endpoint.\n", __func__); >> + return -ENXIO; >> + } > > Looking at the caller, gserial_connect(), none of the error > conditions above look possible. > I re-look the code and do some tests, I found the checking is necessary. Cause we get the port number from the console->index, if the cmdline is not set the ttyGS0 as the console, the console->index will be -1 that is a wrong value. Also the serial.c file will create 1 usb-to-seial port as default (default n_ports = 1), so we need to check the port and the endpoint of the port. So I think here checking is necessary and I have tested it. -- Baolin.wang Best Regards -- 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/