Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753992AbeAGP5h (ORCPT + 1 other); Sun, 7 Jan 2018 10:57:37 -0500 Received: from fllnx210.ext.ti.com ([198.47.19.17]:16797 "EHLO fllnx210.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753452AbeAGP5f (ORCPT ); Sun, 7 Jan 2018 10:57:35 -0500 Subject: Re: [PATCH v6 10/10] clocksource: timer-dm: Check prescaler value To: Ladislav Michl , CC: , , , , , , , , , , References: <1514887799-24605-1-git-send-email-j-keerthy@ti.com> <1514887799-24605-11-git-send-email-j-keerthy@ti.com> <20180104224713.GA11557@lenoch> From: Keerthy Message-ID: Date: Sun, 7 Jan 2018 21:26:44 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: <20180104224713.GA11557@lenoch> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On 1/5/2018 4:17 AM, Ladislav Michl wrote: > On Tue, Jan 02, 2018 at 03:39:59PM +0530, Keerthy wrote: >> From: Ladislav Michl >> >> Invalid prescaler value is silently ignored. Fix that >> by returning -EINVAL in such case. As invalid value >> disabled use of the prescaler, use -1 explicitely for >> that purpose. >> >> Signed-off-by: Ladislav Michl >> --- >> drivers/clocksource/timer-dm.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/clocksource/timer-dm.c b/drivers/clocksource/timer-dm.c >> index 60db173..01a9cb0 100644 >> --- a/drivers/clocksource/timer-dm.c >> +++ b/drivers/clocksource/timer-dm.c >> @@ -672,6 +672,9 @@ int omap_dm_timer_set_prescaler(struct omap_dm_timer *timer, int prescaler) >> if (prescaler >= 0x00 && prescaler <= 0x07) { >> l |= OMAP_TIMER_CTRL_PRE; >> l |= prescaler << 2; >> + } else { >> + if (prescaler != -1) >> + return -EINVAL; > > Argh... This is actually wrong, as it leaves timer enabled. > I suggest simply dropping this patch and I'll rethink whole > approach a bit later (and better). Okay. I hope the rest 9 patches work well for you. > >> } >> omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l); >> > > Sorry for the noise, > ladis >