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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3161FC46467 for ; Wed, 6 Apr 2022 00:40:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1836732AbiDFAjW (ORCPT ); Tue, 5 Apr 2022 20:39:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32792 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1389310AbiDENdn (ORCPT ); Tue, 5 Apr 2022 09:33:43 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D547BE886D for ; Tue, 5 Apr 2022 05:37:25 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9BE56D6E; Tue, 5 Apr 2022 05:37:25 -0700 (PDT) Received: from [10.57.41.19] (unknown [10.57.41.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A44BC3F5A1; Tue, 5 Apr 2022 05:37:24 -0700 (PDT) Message-ID: Date: Tue, 5 Apr 2022 13:37:19 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH] ALSA: emu10k1: Stop using iommu_present() Content-Language: en-GB To: Takashi Iwai Cc: perex@perex.cz, tiwai@suse.com, iommu@lists.linux-foundation.org, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org References: <5ac9b54285b2189b848da2595408eb3cae8e5e9d.1649160813.git.robin.murphy@arm.com> From: Robin Murphy In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022-04-05 13:29, Takashi Iwai wrote: > On Tue, 05 Apr 2022 14:13:33 +0200, > Robin Murphy wrote: >> >> iommu_get_domain_for_dev() is already perfectly happy to return NULL >> if the given device has no IOMMU. Drop the unnecessary check. >> >> Signed-off-by: Robin Murphy > > This will change the code behavior. The current code does nothing if > no IOMMU is found, but after your removal of the check, the code > reaches to emu->iommu_workaround = true incorrectly. Ah, right you are - I should have looked more closely at the second check, where of course "domain &&" wants tweaking to "!domain ||" as well. I'll send a v2 in a bit... Thanks, Robin. > > > thanks, > > Takashi > >> --- >> sound/pci/emu10k1/emu10k1_main.c | 3 --- >> 1 file changed, 3 deletions(-) >> >> diff --git a/sound/pci/emu10k1/emu10k1_main.c b/sound/pci/emu10k1/emu10k1_main.c >> index 86cc1ca025e4..5ffab343b89c 100644 >> --- a/sound/pci/emu10k1/emu10k1_main.c >> +++ b/sound/pci/emu10k1/emu10k1_main.c >> @@ -1751,9 +1751,6 @@ static void snd_emu10k1_detect_iommu(struct snd_emu10k1 *emu) >> >> emu->iommu_workaround = false; >> >> - if (!iommu_present(emu->card->dev->bus)) >> - return; >> - >> domain = iommu_get_domain_for_dev(emu->card->dev); >> if (domain && domain->type == IOMMU_DOMAIN_IDENTITY) >> return; >> -- >> 2.28.0.dirty >>