From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 832A6C433E0 for ; Tue, 28 Jul 2020 07:39:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 61EB622B3F for ; Tue, 28 Jul 2020 07:39:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727905AbgG1Hjy (ORCPT ); Tue, 28 Jul 2020 03:39:54 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:50334 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727045AbgG1Hjy (ORCPT ); Tue, 28 Jul 2020 03:39:54 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 7A34D52C142BC77B2F15; Tue, 28 Jul 2020 15:39:51 +0800 (CST) Received: from [10.174.187.22] (10.174.187.22) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.487.0; Tue, 28 Jul 2020 15:39:40 +0800 Subject: Re: [RESEND PATCH] drivers: arm arch timer: Correct fault programming of CNTKCTL_EL1.EVNTI To: , , , References: <20200717092104.15428-1-zhukeqian1@huawei.com> CC: Marc Zyngier , Catalin Marinas , Will Deacon , James Morse , "Suzuki K Poulose" , From: zhukeqian Message-ID: Date: Tue, 28 Jul 2020 15:39:40 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <20200717092104.15428-1-zhukeqian1@huawei.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.187.22] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Friendly ping. Is this an effective bugfix? On 2020/7/17 17:21, Keqian Zhu wrote: > ARM virtual counter supports event stream. It can only trigger an event > when the trigger bit of CNTVCT_EL0 changes from 0 to 1 (or from 1 to 0), > so the actual period of event stream is 2 ^ (cntkctl_evnti + 1). For > example, when the trigger bit is 0, then it triggers an event for every > two cycles. > > Signed-off-by: Keqian Zhu > --- > drivers/clocksource/arm_arch_timer.c | 17 ++++++++++++++--- > 1 file changed, 14 insertions(+), 3 deletions(-) > > diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c > index ecf7b7db2d05..06d99a4b1b9b 100644 > --- a/drivers/clocksource/arm_arch_timer.c > +++ b/drivers/clocksource/arm_arch_timer.c > @@ -799,10 +799,20 @@ static void __arch_timer_setup(unsigned type, > static void arch_timer_evtstrm_enable(int divider) > { > u32 cntkctl = arch_timer_get_cntkctl(); > + int cntkctl_evnti; > + > + /* > + * Note that it can only trigger an event when the trigger bit > + * of CNTVCT_EL0 changes from 1 to 0 (or from 0 to 1), so the > + * actual period of event stream is 2 ^ (cntkctl_evnti + 1). > + */ > + cntkctl_evnti = divider - 1; > + cntkctl_evnti = min(cntkctl_evnti, 15); > + cntkctl_evnti = max(cntkctl_evnti, 0); > > cntkctl &= ~ARCH_TIMER_EVT_TRIGGER_MASK; > /* Set the divider and enable virtual event stream */ > - cntkctl |= (divider << ARCH_TIMER_EVT_TRIGGER_SHIFT) > + cntkctl |= (cntkctl_evnti << ARCH_TIMER_EVT_TRIGGER_SHIFT) > | ARCH_TIMER_VIRT_EVT_EN; > arch_timer_set_cntkctl(cntkctl); > arch_timer_set_evtstrm_feature(); > @@ -816,10 +826,11 @@ static void arch_timer_configure_evtstream(void) > /* Find the closest power of two to the divisor */ > evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ; > pos = fls(evt_stream_div); > - if (pos > 1 && !(evt_stream_div & (1 << (pos - 2)))) > + if ((pos == 1) || (pos > 1 && !(evt_stream_div & (1 << (pos - 2))))) > pos--; > + > /* enable event stream */ > - arch_timer_evtstrm_enable(min(pos, 15)); > + arch_timer_evtstrm_enable(pos); > } > > static void arch_counter_set_user_access(void) >