From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759612AbcAKLIb (ORCPT ); Mon, 11 Jan 2016 06:08:31 -0500 Received: from foss.arm.com ([217.140.101.70]:54414 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758175AbcAKLIa (ORCPT ); Mon, 11 Jan 2016 06:08:30 -0500 Subject: Re: [PATCH v5 05/11] arm-cci PMU: Delay counter writes to pmu_enable To: Mark Rutland References: <1451908490-2615-1-git-send-email-suzuki.poulose@arm.com> <1451908490-2615-6-git-send-email-suzuki.poulose@arm.com> <20160104192401.GD17127@leverpostej> <568B93F1.8050202@arm.com> <20160111104609.GE6499@leverpostej> Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, arm@kernel.org, punit.agrawal@arm.com, peterz@infradead.org From: "Suzuki K. Poulose" Message-ID: <56938D2B.7050700@arm.com> Date: Mon, 11 Jan 2016 11:08:27 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <20160111104609.GE6499@leverpostej> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/01/16 10:46, Mark Rutland wrote: > On Tue, Jan 05, 2016 at 09:59:13AM +0000, Suzuki K. Poulose wrote: >> On 04/01/16 19:24, Mark Rutland wrote: >>> On Mon, Jan 04, 2016 at 11:54:44AM +0000, Suzuki K. Poulose wrote: >> The pmu is not disabled while we are in overflow irq handler. Hence there may >> not be a pmu_enable() which would set the period for the counter which >> overflowed, if defer the write in that case. Is that assumption wrong ? > > As the driver stands today, yes. > > However, wouldn't it make more sense to disable the PMU for the overflow > handler, such that we can reuse the batching logic? None of the PMU drivers do that AFAIK. Hence, didn't want to change it for CCI. We could use the batching logic, if decide to do so. I can go ahead with that if there are no other side effects with that. Suzuki