From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from bh-25.webhostbox.net ([208.91.199.152]:45942 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751568AbbKXCcX (ORCPT ); Mon, 23 Nov 2015 21:32:23 -0500 Subject: Re: [PATCH v4 3/5] watchdog: ts4800: add driver for TS-4800 watchdog To: Damien Riegel , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-watchdog@vger.kernel.org References: <1448291861-28543-1-git-send-email-damien.riegel@savoirfairelinux.com> <1448291861-28543-4-git-send-email-damien.riegel@savoirfairelinux.com> Cc: Lee Jones , robh+dt@kernel.org, shawnguo@kernel.org, kernel@pengutronix.de, wim@iguana.be, sameo@linux.intel.com, dinh.linux@gmail.com, Arnd Bergmann , kernel@savoirfairelinux.com From: Guenter Roeck Message-ID: <5653CC2F.8080608@roeck-us.net> Date: Mon, 23 Nov 2015 18:32:15 -0800 MIME-Version: 1.0 In-Reply-To: <1448291861-28543-4-git-send-email-damien.riegel@savoirfairelinux.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-watchdog-owner@vger.kernel.org List-Id: linux-watchdog@vger.kernel.org Hi Damien, On 11/23/2015 07:17 AM, Damien Riegel wrote: > This watchdog is instantiated in a FPGA that is memory mapped. It is > made of only one register, called the feed register. Writing to this > register will re-arm the watchdog for a given time (and enable it if it > was disable). It can be disabled by writing a special value into it. > > It is part of a syscon block, and the watchdog register offset in this > block varies from board to board. This offset is passed in the syscon > property after the phandle to the syscon node. > > Signed-off-by: Damien Riegel > --- [ ... ] > + > +static int ts4800_wdt_set_timeout(struct watchdog_device *wdd, > + unsigned int timeout) > +{ > + struct ts4800_wdt *wdt = watchdog_get_drvdata(wdd); > + int i; > + > + for (i = 0; i <= MAX_TIMEOUT_INDEX; i++) { > + if (ts4800_wdt_map[i].timeout >= timeout) > + break; > + } If the loop does not break, i will have a value of MAX_TIMEOUT_INDEX + 1, or 2, pointing after the end of the table. That should never happen, but still ... I preferred the earlier version, where you had an extra function. Only my suggestion was to have that function return MAX_TIMEOUT_INDEX instead of an error. Alternatively, the check above needs to be "i < MAX_TIMEOUT_INDEX". Guenter