From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751739AbcFCH32 (ORCPT ); Fri, 3 Jun 2016 03:29:28 -0400 Received: from gloria.sntech.de ([95.129.55.99]:50730 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751082AbcFCH30 convert rfc822-to-8bit (ORCPT ); Fri, 3 Jun 2016 03:29:26 -0400 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Shawn Lin Cc: Xing Zheng , Shawn Lin , linux-rockchip@lists.infradead.org, Stephen Boyd , linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org Subject: Re: [PATCH 2/2] clk: rockchip: remove ROCKCHIP_SOFTRST_HIWORD_MASK for rockchip platform Date: Fri, 03 Jun 2016 09:29:03 +0200 Message-ID: <1853369.vjRjVRadgx@diego> User-Agent: KMail/4.14.10 (Linux/4.4.0-1-amd64; KDE/4.14.14; x86_64; ; ) In-Reply-To: <7fdf43a9-58d4-d6a8-d863-a7e265c93a06@kernel-upstream.org> References: <1464915288-10877-1-git-send-email-shawn.lin@rock-chips.com> <5750DC85.4040400@rock-chips.com> <7fdf43a9-58d4-d6a8-d863-a7e265c93a06@kernel-upstream.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Shawn, Am Freitag, 3. Juni 2016, 11:35:32 schrieb Shawn Lin: > 在 2016/6/3 9:25, Xing Zheng 写道: > > On 2016年06月03日 08:54, Shawn Lin wrote: > >> I check all the Socs including RK2928/3000/3066/3028X/316X/312X/ > >> 3190/3188/3228/3368/3399/3036, and find all of them use high 16-bit > >> as write mask. Obviously we don't need ROCKCHIP_SOFTRST_HIWORD_MASK > >> any more(actually I don't know why we need it before). This patch > >> removes it to simplify the code and save a little cpu cycle when calling > >> assert or deassert callback. > > > > In my opinion, this flag can be used for compatibility, we can not > > ensure that our SoCs will not use the 32bit SOFTRST_CONs in future. > > > > Thanks. > > Thanks for sharing your thought. > > I'm not 100% sure, but I'm 99% sure about we won't let > it happened. You have to consider the backward compatibility > rather than the future ones. If you got a chip with 10 bit, or > 8bit for SOFTRST_CONX, so how do you wanna deal with it? > Should we now add ROCKCHIP_SOFTRST_X_BIT_MASK? :) older SoCs like the rk2818 (ARM9-based) do actually use 32bit softrst registers. And if I ever get my hands on one of those, I'd actually try to support it :-) . So I'd really like to keep the flag. Heiko