From patchwork Wed Jun 29 08:48:14 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephan Gerhold X-Patchwork-Id: 586087 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CCF8C43334 for ; Wed, 29 Jun 2022 08:48:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232909AbiF2Iss (ORCPT ); Wed, 29 Jun 2022 04:48:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232904AbiF2Isr (ORCPT ); Wed, 29 Jun 2022 04:48:47 -0400 Received: from mx.kernkonzept.com (serv1.kernkonzept.com [IPv6:2a01:4f8:1c1c:b490::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 017843CA64; Wed, 29 Jun 2022 01:48:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=kernkonzept.com; s=mx1; h=Content-Transfer-Encoding:MIME-Version:References :In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=nysqDoSIXnF5KIZKd2MprpDgDytNBqd05oO/1KPwa/A=; b=HKHZiMHDaaiICoTViS7cSvKxeL pULqDCx+WfoeEznxIym2jHCh+xJymnby3nY4aGmT/7PCswi3irCJ6hs3owLfWJcj3TzDw30/D62Wu 16lnkaKWLHZIsWwfpbgXzFLQf97JPapF8kEgMVSTU76hPbxbG+myGjQqKAniiFS2RAGPTYoYib1w4 krfgoxhOSPGJu3pb6DNBACcrMFbPO7sVnvIIeUHwb7MQJPPNJVMs9VqS9r3oHDijt2pi65CEfN231 jyK5d4YTcYVgavOPMhr9UkIu7ogYMCza4NUc0V0VmEtfeVh2FktbJ0UG6zn4K5ihkW7fORbFgL9bj pr0W48tQ==; Received: from [10.22.3.24] (helo=kernkonzept.com) by mx.kernkonzept.com with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94.2) id 1o6TNG-006RUL-Un; Wed, 29 Jun 2022 10:48:38 +0200 From: Stephan Gerhold To: Wim Van Sebroeck , Guenter Roeck Cc: Loic Poulain , linux-watchdog@vger.kernel.org, linux-arm-msm@vger.kernel.org, Stephan Gerhold Subject: [PATCH v2 1/3] watchdog: pm8916_wdt: Avoid read of write-only PET register Date: Wed, 29 Jun 2022 10:48:14 +0200 Message-Id: <20220629084816.125515-2-stephan.gerhold@kernkonzept.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220629084816.125515-1-stephan.gerhold@kernkonzept.com> References: <20220629084816.125515-1-stephan.gerhold@kernkonzept.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org PMIC_WD_RESET_PET is a write-only register that is used to ping the watchdog. It does not make sense to use read-modify-write for it: a register read will never return anything but zero. (And actually even if it did we would still want to write again to ensure the watchdog is pinged.) Reduce the overhead for the watchdog ping slightly by using regmap_write() directly instead. Signed-off-by: Stephan Gerhold Reviewed-by: Guenter Roeck Reviewed-by: Loic Poulain --- Changes in v2: Add Guenter's Reviewed-by --- drivers/watchdog/pm8916_wdt.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/watchdog/pm8916_wdt.c b/drivers/watchdog/pm8916_wdt.c index 0937b8d33104..670cd79f4cf9 100644 --- a/drivers/watchdog/pm8916_wdt.c +++ b/drivers/watchdog/pm8916_wdt.c @@ -58,9 +58,8 @@ static int pm8916_wdt_ping(struct watchdog_device *wdev) { struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev); - return regmap_update_bits(wdt->regmap, - wdt->baseaddr + PON_PMIC_WD_RESET_PET, - WATCHDOG_PET_BIT, WATCHDOG_PET_BIT); + return regmap_write(wdt->regmap, wdt->baseaddr + PON_PMIC_WD_RESET_PET, + WATCHDOG_PET_BIT); } static int pm8916_wdt_configure_timers(struct watchdog_device *wdev)