From patchwork Wed Nov 25 15:42:49 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jisheng Zhang X-Patchwork-Id: 7700531 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 17E359F2E9 for ; Wed, 25 Nov 2015 15:48:40 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4A22A207A6 for ; Wed, 25 Nov 2015 15:48:39 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 70F44207A2 for ; Wed, 25 Nov 2015 15:48:38 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1a1cHZ-0001nW-Vi; Wed, 25 Nov 2015 15:46:58 +0000 Received: from mx0a-0016f401.pphosted.com ([67.231.148.174]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1a1cHM-0001S5-Mw for linux-arm-kernel@lists.infradead.org; Wed, 25 Nov 2015 15:46:54 +0000 Received: from pps.filterd (m0045849.ppops.net [127.0.0.1]) by mx0a-0016f401.pphosted.com (8.15.0.59/8.15.0.59) with SMTP id tAPFjHAc001872; Wed, 25 Nov 2015 07:46:19 -0800 Received: from sc-exch02.marvell.com ([199.233.58.182]) by mx0a-0016f401.pphosted.com with ESMTP id 1yd8gnh54q-1 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Wed, 25 Nov 2015 07:46:18 -0800 Received: from SC-EXCH02.marvell.com (10.93.176.82) by SC-EXCH02.marvell.com (10.93.176.82) with Microsoft SMTP Server (TLS) id 15.0.1044.25; Wed, 25 Nov 2015 07:46:17 -0800 Received: from maili.marvell.com (10.93.176.43) by SC-EXCH02.marvell.com (10.93.176.82) with Microsoft SMTP Server id 15.0.1044.25 via Frontend Transport; Wed, 25 Nov 2015 07:46:17 -0800 Received: from xhacker.marvell.com (unknown [10.37.135.134]) by maili.marvell.com (Postfix) with ESMTP id 0AA953F704B; Wed, 25 Nov 2015 07:46:16 -0800 (PST) From: Jisheng Zhang To: , Subject: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Date: Wed, 25 Nov 2015 23:42:49 +0800 Message-ID: <1448466169-5230-1-git-send-email-jszhang@marvell.com> X-Mailer: git-send-email 2.6.2 MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2015-11-25_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-1511250274 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20151125_074645_027303_8F82E69E X-CRM114-Status: UNSURE ( 9.65 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -2.6 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jisheng Zhang , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Let's assume the counter value is 0xf000000, the pistachio clocksource read cycles function would return 0xffffffff0fffffff, but it should return 0xfffffff. We fix this issue by calculating bitwise-not counter, then cast to cycle_t. Signed-off-by: Jisheng Zhang --- drivers/clocksource/time-pistachio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/clocksource/time-pistachio.c b/drivers/clocksource/time-pistachio.c index bba6799..3269d9e 100644 --- a/drivers/clocksource/time-pistachio.c +++ b/drivers/clocksource/time-pistachio.c @@ -84,7 +84,7 @@ pistachio_clocksource_read_cycles(struct clocksource *cs) counter = gpt_readl(pcs->base, TIMER_CURRENT_VALUE, 0); raw_spin_unlock_irqrestore(&pcs->lock, flags); - return ~(cycle_t)counter; + return (cycle_t)~counter; } static u64 notrace pistachio_read_sched_clock(void)