From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754623AbbKMMfd (ORCPT ); Fri, 13 Nov 2015 07:35:33 -0500 Received: from mx0b-0016f401.pphosted.com ([67.231.156.173]:24591 "EHLO mx0b-0016f401.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750878AbbKMMfc (ORCPT ); Fri, 13 Nov 2015 07:35:32 -0500 From: Jisheng Zhang To: , , CC: , , Jisheng Zhang Subject: [PATCH v2] clocksource/drivers/dw_apb_timer: Use {readl|writel}_relaxed Date: Fri, 13 Nov 2015 20:31:23 +0800 Message-ID: <1447417883-7881-1-git-send-email-jszhang@marvell.com> X-Mailer: git-send-email 2.6.2 MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2015-11-13_11:,, signatures=0 X-Proofpoint-Spam-Details: rule=inbound_notspam policy=inbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1507310000 definitions=main-1511130211 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The driver is safe to use the relaxed version. From another side, the relaxed io accessor macros are available on all architectures now, so we can use the relaxed versions to get a trivial overall system performance improvement and reduce the latency a bit on some architectures. Signed-off-by: Jisheng Zhang --- since v1: - correct the wrong sentence in commit msg about writel performance on CA9 with outer L2 cache. Thank Arnd for pointing out this in another thread drivers/clocksource/dw_apb_timer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/clocksource/dw_apb_timer.c b/drivers/clocksource/dw_apb_timer.c index c76c750..04282ee 100644 --- a/drivers/clocksource/dw_apb_timer.c +++ b/drivers/clocksource/dw_apb_timer.c @@ -51,13 +51,13 @@ clocksource_to_dw_apb_clocksource(struct clocksource *cs) static unsigned long apbt_readl(struct dw_apb_timer *timer, unsigned long offs) { - return readl(timer->base + offs); + return readl_relaxed(timer->base + offs); } static void apbt_writel(struct dw_apb_timer *timer, unsigned long val, unsigned long offs) { - writel(val, timer->base + offs); + writel_relaxed(val, timer->base + offs); } static void apbt_disable_int(struct dw_apb_timer *timer) -- 2.6.2