From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20D47C83003 for ; Wed, 29 Apr 2020 07:20:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F272420775 for ; Wed, 29 Apr 2020 07:20:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588144844; bh=MC7v/B/AUB+89bATTGb3hziKs1OjKTAH6JyUhQGNvPI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=wramAFVAuQiYf+J5ToXObH4qRo9NS4TXqDfXqWi1gk2bVPuICml5DjdlCEWm4zU2W 0t3EKNJo8GGg5cGaiNg1xkQv2++XpD9fGLfoKA8+gBm8YQ8FNLdoQkOqShN7Esx3/n qs163g6ozGSc7laABV38gB3rMPkMiIhpZFcoUINY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726508AbgD2HUl (ORCPT ); Wed, 29 Apr 2020 03:20:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:57414 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726483AbgD2HUl (ORCPT ); Wed, 29 Apr 2020 03:20:41 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 884C62076B; Wed, 29 Apr 2020 07:20:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588144839; bh=MC7v/B/AUB+89bATTGb3hziKs1OjKTAH6JyUhQGNvPI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PkjuO7H3O+1g5LH2lMW2dsDVrHOO7kKFPejUHYQdMR/RVCWUu1Q5uR3jxTV41YQVA hr9CwS7A4WPgsZW+Zu3VU4EIdX1PRdNZ4fOufw2vFT2iTQEFzs7lr2PpwIUe4rm69/ pk650QeRHER3wPv6jTm0tc/KPTTk6cp+YveQTt+I= Date: Wed, 29 Apr 2020 09:20:36 +0200 From: Greg KH To: mani@kernel.org Cc: johan@kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, patong.mxl@gmail.com Subject: Re: [PATCH 1/2] usb: serial: Add MaxLinear/Exar USB to Serial driver Message-ID: <20200429072036.GA2045202@kroah.com> References: <20200428195651.6793-1-mani@kernel.org> <20200428195651.6793-2-mani@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200428195651.6793-2-mani@kernel.org> Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, Apr 29, 2020 at 01:26:50AM +0530, mani@kernel.org wrote: > From: Manivannan Sadhasivam > > Add support for MaxLinear/Exar USB to Serial converters. This driver > only supports XR21V141X series but provision has been made to support > other series in future. > > This driver is inspired from the initial one submitted by Patong Yang: > > https://patchwork.kernel.org/patch/10543261/ > > While the initial driver was a custom tty USB driver exposing whole > new serial interface ttyXRUSBn, this version is completely based on USB > serial core thus exposing the interfaces as ttyUSBn. This will avoid > the overhead of exposing a new USB serial interface which the userspace > tools are unaware of. Nice work! Some comments below: > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * MaxLinear/Exar USB to Serial driver > + * > + * Based on initial driver written by Patong Yang > + * > + * Copyright (c) 2020 Manivannan Sadhasivam > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "xr_serial.h" No need for a .h file for a single .c file. > +static int xr_get_reg(struct usb_serial_port *port, u8 block, u16 reg, > + u16 *val) > +{ > + struct usb_serial *serial = port->serial; > + struct xr_port_private *port_priv = usb_get_serial_port_data(port); > + void *dmabuf; > + int ret = -EINVAL; > + > + dmabuf = kmalloc(sizeof(reg), GFP_KERNEL); So that is 2 bytes? > + if (!dmabuf) > + return -ENOMEM; > + > + if (port_priv->idProduct == XR21V141X_ID) { > + /* XR21V141X uses custom command for reading UART registers */ > + ret = usb_control_msg(serial->dev, > + usb_rcvctrlpipe(serial->dev, 0), > + XR_GET_XR21V141X, > + USB_DIR_IN | USB_TYPE_VENDOR, 0, > + reg | (block << 8), dmabuf, > + port_priv->reg_width, > + USB_CTRL_SET_TIMEOUT); > + } > + > + if (ret == port_priv->reg_width) { > + memcpy(val, dmabuf, port_priv->reg_width); But here you copy ->reg_width bytes in? How do you know val can hold that much? It's only set to be 1, so you copy 1 byte to a 16bit value? What part of the 16bits did you just copy those 8 bits to (hint, think cpu endian issues...) That feels really really odd and a bit broken. > --- /dev/null > +++ b/drivers/usb/serial/xr_serial.h > @@ -0,0 +1,103 @@ > +/* SPDX-License-Identifier: GPL-2.0+ */ Are you sure about the "+"? I have to ask :) > + > +#ifndef __LINUX_USB_SERIAL_XR_SERIAL_H > +#define __LINUX_USB_SERIAL_XR_SERIAL_H As you will drop this file, just a general statement, no need for __LINUX as this is all Linux :) thanks, greg k-h