From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f53.google.com (mail-ej1-f53.google.com [209.85.218.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 72794BA53; Wed, 4 Jan 2023 22:04:47 +0000 (UTC) Received: by mail-ej1-f53.google.com with SMTP id ud5so86061076ejc.4; Wed, 04 Jan 2023 14:04:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=VAgESyffyGfL2EhiYgHo7ieKIsVwn7XJhQmStMSRKhc=; b=phZ4NEuz02LsQ6So2V3GDbdOgwyUdlRwWhE5T2GTNM/a5pN71DO/CDYus16Rv/B0ZK pJ0qqJvDjI4bKk9DQPd/Lrk5Jjy9BrpWHESRd9N09T8gtnRjrW9MoNVa+KtRnr4zLubD 7tTmunNmEQ3JXQcKYJ05+jf/lTcKuELd6zucImxruAGzLylewyGpovnNdY3icMfC3m7E n7hW6kSKL78yD7ihTeiIvHudmokzhrkGqT0vsMGR08nr0JnlWzpLRS9K2VxR0fvV6LYA ZXe2NwMbfNEoNtoJ/Gjw8WW2adAZM36yGRp+BE6Vx39jQA4BQqJJ8ifhw03MCZAgOd1R T59w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=VAgESyffyGfL2EhiYgHo7ieKIsVwn7XJhQmStMSRKhc=; b=wtq8l1+VBX5LhvioqOsv2AB/xXom8DMhfrrVd4tLsaP+ML+Cnj1KGQv+osROIVqZuF OlQTgRKdij4b+1LIN/oGcj4aApnZRJ2woKOp7zHxeuQSGnaOQYvX6rC8cXrfYhRtp4WM NMk6gMRCH0HeEQS0gjWhxIwd8absyhlcFeD5SVg0p9F/1MmAlxp7rX7HL5rTySe8HsZm o+cLNEtBnmiy8JXHa0vwdpFudybomAMRp/7NiAOUKn/8wSiFOpuiMQp6UPRdpT4sm5nD RrOr40XS1JIWfrJz//j6x/SDeQVpXPzitqGlq/DJSwD52hRlmTit9Yxz+X9OK9MvQhVr dJwQ== X-Gm-Message-State: AFqh2kp4KD1BO5Ydpad2eJ8I64fHZOb3KBM7PMr89F7BcByWGm5MoPlx CB4GvaCMi03aa+EBZ/Wmw1M= X-Google-Smtp-Source: AMrXdXueZ4a9lP4WZD0oUUo0ysvovdN+8hgWpPMcryijlJBywkg9NIsmu669fcPxczi1QTbkkiMVIw== X-Received: by 2002:a17:906:ecf7:b0:7c4:f6e4:3e92 with SMTP id qt23-20020a170906ecf700b007c4f6e43e92mr49873730ejb.31.1672869885740; Wed, 04 Jan 2023 14:04:45 -0800 (PST) Received: from jernej-laptop.localnet (82-149-19-102.dynamic.telemach.net. [82.149.19.102]) by smtp.gmail.com with ESMTPSA id jg34-20020a170907972200b0084cb8589523sm5336958ejc.139.2023.01.04.14.04.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Jan 2023 14:04:44 -0800 (PST) From: Jernej =?utf-8?B?xaBrcmFiZWM=?= To: Joerg Roedel , Will Deacon , Robin Murphy , Chen-Yu Tsai , Krzysztof Kozlowski , Rob Herring , Samuel Holland Cc: iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Maxime Ripard , Samuel Holland Subject: Re: [PATCH v2 2/6] iommu/sun50i: Track masters attached to the domain Date: Wed, 04 Jan 2023 23:04:43 +0100 Message-ID: <8201525.NyiUUSuA9g@jernej-laptop> In-Reply-To: <20230103010903.11181-3-samuel@sholland.org> References: <20230103010903.11181-1-samuel@sholland.org> <20230103010903.11181-3-samuel@sholland.org> Precedence: bulk X-Mailing-List: linux-sunxi@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Dne torek, 03. januar 2023 ob 02:08:59 CET je Samuel Holland napisal(a): > The refcount logic here is broken. The refcount is initialized to 1 with > no devices attached, so it will be decremented back to 1 when the last > device is detached. However, refcount_dec_and_test() returns true only > when the refcount gets decremented to zero, so the domain will never be > cleaned up, and the hardware will never be disabled. > > Replace the refcount with a mask of masters attached to the domain. The > domain can be cleaned up when the last master detaches. This mask is > also necessary to correctly set the bypass register. > > Fixes: 4100b8c229b3 ("iommu: Add Allwinner H6 IOMMU driver") > Signed-off-by: Samuel Holland Reviewed-by: Jernej Skrabec Best regards, Jernej