linux-kernel - RE: [PATCH -next] serial: imx: remove set but not used variable 'rtsirq'

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <VI1PR0402MB3600A7368D538E3B6D044C5FFF130@VI1PR0402MB3600.eurprd04.prod.outlook.com>
Date:   Thu, 20 Sep 2018 09:41:18 +0000
From:   Andy Duan <fugang.duan@....com>
To:     Leonard Crestez <leonard.crestez@....com>,
        "yuehaibing@...wei.com" <yuehaibing@...wei.com>,
        "u.kleine-koenig@...gutronix.de" <u.kleine-koenig@...gutronix.de>,
        "jslaby@...e.cz" <jslaby@...e.cz>
CC:     "linux-serial@...r.kernel.org" <linux-serial@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "A.s. Dong" <aisheng.dong@....com>, Abel Vesa <abel.vesa@....com>,
        Anson Huang <anson.huang@....com>,
        Bough Chen <haibo.chen@....com>,
        Cosmin Samoila <cosmin.samoila@....com>,
        Daniel Baluta <daniel.baluta@....com>, Han Xu <han.xu@....com>,
        Jacky Bai <ping.bai@....com>, Jun Li <jun.li@....com>,
        Leo Zhang <leo.zhang@....com>,
        Leonard Crestez <leonard.crestez@....com>,
        Peng Fan <peng.fan@....com>, Peter Chen <peter.chen@....com>,
        Ranjani Vaidyanathan <ranjani.vaidyanathan@....com>,
        Robert Chiras <robert.chiras@....com>,
        Robin Gong <yibin.gong@....com>,
        Shenwei Wang <shenwei.wang@....com>,
        Viorel Suman <viorel.suman@....com>,
        Zening Wang <zening.wang@....com>,
        "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        "kernel-janitors@...r.kernel.org" <kernel-janitors@...r.kernel.org>
Subject: RE: [PATCH -next] serial: imx: remove set but not used variable
 'rtsirq'

From: Leonard Crestez Sent: 2018年9月20日 16:51
> On Thu, 2018-09-20 at 08:45 +0200, Jiri Slaby wrote:
> > On 09/20/2018, 03:58 AM, YueHaibing wrote:
> > > Fixes gcc '-Wunused-but-set-variable' warning:
> > >
> > > drivers/tty/serial/imx.c: In function 'imx_uart_probe':
> > > drivers/tty/serial/imx.c:2198:20: warning:
> > >  variable 'rtsirq' set but not used [-Wunused-but-set-variable]
> > >
> > > diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c @@
> > > -2220,7 +2220,6 @@ static int imx_uart_probe(struct
> platform_device
> > > *pdev)
> > >
> > >  	rxirq = platform_get_irq(pdev, 0);
> > >  	txirq = platform_get_irq(pdev, 1);
> > > -	rtsirq = platform_get_irq(pdev, 2);
> >
> > I am not sure this is correct. platform_get_irq has side effects (like
> > enabling the IRQ). Are you sure this won't change the behaviour (this
> > is question mostly to IMX fellows)?
> 
> As far as I can tell there was a request_irq call for rtsirq which was
> removed by mistake in commit afe9cbb1a6ad ("serial: imx: drop support
> for IRDA"):
> 
> -               /* do not use RTS IRQ on IrDA */
> -               if (!USE_IRDA(sport)) {
> -                       ret = devm_request_irq(&pdev->dev, rtsirq,
> -                                              imx_rtsint, 0,
> -
> dev_name(&pdev->dev), sport);
> -                       if (ret)
> -                               return ret;
> -               }
> 
> This should have just removed the IRDA check and request rtsirq
> unconditionally. Nobody noticed this by testing RTS on imx1, this is an old
> chip and later variants have a single combined irq.
> 
> The correct fix for the warning would be to restore that request_irq.
> 
> --
> Regards,
> Leonard

Yes, your explain is very correct! Thanks for your comment.
We should restore rtsirq request that for i.MX1.

Regards,
Andy Duan