From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751665AbbDKEv6 (ORCPT ); Sat, 11 Apr 2015 00:51:58 -0400 Received: from mail-pa0-f53.google.com ([209.85.220.53]:32834 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750906AbbDKEv5 (ORCPT ); Sat, 11 Apr 2015 00:51:57 -0400 Date: Sat, 11 Apr 2015 10:21:44 +0530 From: Sudip Mukherjee To: Giedrius =?utf-8?Q?Statkevi=C4=8Dius?= Cc: lidza.louina@gmail.com, markh@compro.net, gregkh@linuxfoundation.org, driverdev-devel@linuxdriverproject.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/2 RESEND] staging: dgnc: remove dead code in dgnc_tty_write() Message-ID: <20150411045144.GA3496@sudip-PC> References: <1428677335-6853-1-git-send-email-giedrius.statkevicius@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1428677335-6853-1-git-send-email-giedrius.statkevicius@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 10, 2015 at 05:48:54PM +0300, Giedrius Statkevičius wrote: > Remove the dead code protected by in_user in dgnc_tty_write() because it is set > to 0 and never changed to 1 thus the code in ifs never gets executed. dgnc_tty_write() is being called by dgnc_tty_put_char() and it is also the write callback function of struct tty_operations, so I think the correct fix will be to use from_user and make it 0 when dgnc_tty_put_char() calls this function else make it 1 to inform the function that the data wil be coming from the userspace. Maybe some thing like this: diff --git a/drivers/staging/dgnc/dgnc_tty.c b/drivers/staging/dgnc/dgnc_tty.c index ce4187f..96eaf5b 100644 --- a/drivers/staging/dgnc/dgnc_tty.c +++ b/drivers/staging/dgnc/dgnc_tty.c @@ -1682,10 +1682,15 @@ static int dgnc_tty_put_char(struct tty_struct *tty, unsigned char c) /* * Simply call tty_write. */ - dgnc_tty_write(tty, &c, 1); + __dgnc_tty_write(tty, &c, 1, 0); return 1; } +static int dgnc_tty_write(struct tty_struct *tty, + const unsigned char *buf, int count) +{ + __dgnc_tty_write(tty, buf, count, 1); +} /* * dgnc_tty_write() @@ -1693,8 +1698,8 @@ static int dgnc_tty_put_char(struct tty_struct *tty, unsigned char c) * Take data from the user or kernel and send it out to the FEP. * In here exists all the Transparent Print magic as well. */ -static int dgnc_tty_write(struct tty_struct *tty, - const unsigned char *buf, int count) +static int __dgnc_tty_write(struct tty_struct *tty, + const unsigned char *buf, int count, int from_user) { struct channel_t *ch = NULL; struct un_t *un = NULL; @@ -1705,7 +1710,6 @@ static int dgnc_tty_write(struct tty_struct *tty, ushort tail; ushort tmask; uint remain; - int from_user = 0; if (tty == NULL || dgnc_TmpWriteBuf == NULL) return 0; regards sudip