Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751182AbeAQFcg (ORCPT + 1 other); Wed, 17 Jan 2018 00:32:36 -0500 Received: from mail-ua0-f193.google.com ([209.85.217.193]:39800 "EHLO mail-ua0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750794AbeAQFcf (ORCPT ); Wed, 17 Jan 2018 00:32:35 -0500 X-Google-Smtp-Source: ACJfBot7hoty6xYfpcEwLrihNc22+LCuxH1+bLWEUvn1y48LC5o/65gqztu9tj51lnsirZqOiND8JA== MIME-Version: 1.0 In-Reply-To: References: <20180116132540.18939-1-jeffy.chen@rock-chips.com> <20180116132540.18939-3-jeffy.chen@rock-chips.com> From: Tomasz Figa Date: Wed, 17 Jan 2018 14:32:11 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 02/13] iommu/rockchip: Suppress unbinding To: Jeffy Chen Cc: linux-kernel@vger.kernel.org, Ricky Liang , Robin Murphy , simon xue , Heiko Stuebner , "open list:ARM/Rockchip SoC..." , "open list:IOMMU DRIVERS" , Joerg Roedel , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Wed, Jan 17, 2018 at 1:23 PM, Tomasz Figa wrote: > On Tue, Jan 16, 2018 at 10:25 PM, Jeffy Chen wrote: >> It's not safe to unbind rockchip IOMMU driver. > > Might be good to explain why it is not safe and actually add that it > does not make any sense for such low level devices. Actually, shouldn't we also remove support for .remove() and module exit? I don't think it's actually feasible to unload this driver. We actually even have ROCKCHIP_IOMMU Kconfig entry defined as bool, so the driver can be only built-in. Best regards, Tomasz