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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 013F3CA9EC0 for ; Mon, 28 Oct 2019 22:20:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BB61C218AC for ; Mon, 28 Oct 2019 22:20:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572301249; bh=VSBk7YAMwCwbsPuvRCBw6UeuvHY7STvzXKIvzV2nyuI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=XH3Ga3nNsyhFD7eVIMrQ0/QEg/mRX7OQNF3VneEcL8Awt60z/+f3XjXoWOjWRLN/R Hm3OaVGi4Yl9ozp1w48oYrVJqvaNCCNOouCWxHyc9y1xTaWLbd2fD8oOZnNOSdRCl0 6X5gJDnWbFK0QXqjR1rxJyzgRABxU4UTCX6GyOFQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727700AbfJ1WUs (ORCPT ); Mon, 28 Oct 2019 18:20:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:33266 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727601AbfJ1WUs (ORCPT ); Mon, 28 Oct 2019 18:20:48 -0400 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0F6A821479; Mon, 28 Oct 2019 22:20:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572301247; bh=VSBk7YAMwCwbsPuvRCBw6UeuvHY7STvzXKIvzV2nyuI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=0gosvq7R5GnXKiYYLDbPH29ONaAKpYHE02ZEPnzDUcqvXqhp72Teg/Ds/g3vOOu+v FG4avd2WmHPRGFFlHNloeY/x+Kqn7qS/tlQLnwyI/SyJIWS26MT+8t3UyWWDNnzYML dc4R4LPqV+P2GObHwW+vgu32hGQhqxFZzIWcYSL4= Date: Mon, 28 Oct 2019 22:20:42 +0000 From: Will Deacon To: Rob Clark Cc: iommu@lists.linux-foundation.org, freedreno@lists.freedesktop.org, Robin Murphy , Rob Clark , Joerg Roedel , "moderated list:ARM SMMU DRIVERS" , open list Subject: Re: [PATCH v2] iommu/arm-smmu: fix "hang" when games exit Message-ID: <20191028222042.GB8532@willie-the-truck> References: <418d8426-f299-1269-2b2e-f86677cf22c2@arm.com> <20191007204906.19571-1-robdclark@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191007204906.19571-1-robdclark@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rob, On Mon, Oct 07, 2019 at 01:49:06PM -0700, Rob Clark wrote: > From: Rob Clark > > When games, browser, or anything using a lot of GPU buffers exits, there > can be many hundreds or thousands of buffers to unmap and free. If the > GPU is otherwise suspended, this can cause arm-smmu to resume/suspend > for each buffer, resulting 5-10 seconds worth of reprogramming the > context bank (arm_smmu_write_context_bank()/arm_smmu_write_s2cr()/etc). > To the user it would appear that the system just locked up. > > A simple solution is to use pm_runtime_put_autosuspend() instead, so we > don't immediately suspend the SMMU device. Please can you reword the subject to be a bit more useful? The commit message is great, but the subject is a bit like "fix bug in code" to me. > Signed-off-by: Rob Clark > --- > v1: original > v2: unconditionally use autosuspend, rather than deciding based on what > consumer does > > drivers/iommu/arm-smmu.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index 3f1d55fb43c4..b7b41f5001bc 100644 > --- a/drivers/iommu/arm-smmu.c > +++ b/drivers/iommu/arm-smmu.c > @@ -289,7 +289,7 @@ static inline int arm_smmu_rpm_get(struct arm_smmu_device *smmu) > static inline void arm_smmu_rpm_put(struct arm_smmu_device *smmu) > { > if (pm_runtime_enabled(smmu->dev)) > - pm_runtime_put(smmu->dev); > + pm_runtime_put_autosuspend(smmu->dev); > } > > static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom) > @@ -1445,6 +1445,9 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) > /* Looks ok, so add the device to the domain */ > ret = arm_smmu_domain_add_master(smmu_domain, fwspec); Please can you put a comment here explaining what this is doing? An abridged version of the commit message is fine. > + pm_runtime_set_autosuspend_delay(smmu->dev, 20); > + pm_runtime_use_autosuspend(smmu->dev); Cheers, Will