From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751549AbcFNGn1 (ORCPT ); Tue, 14 Jun 2016 02:43:27 -0400 Received: from gloria.sntech.de ([95.129.55.99]:33421 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751221AbcFNGnZ convert rfc822-to-8bit (ORCPT ); Tue, 14 Jun 2016 02:43:25 -0400 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Doug Anderson Cc: Xing Zheng , elaine zhang , Tao Huang , Brian Norris , Yakir Yang , Michael Turquette , Stephen Boyd , linux-clk , "linux-arm-kernel@lists.infradead.org" , "open list:ARM/Rockchip SoC..." , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] clk: rockchip: add pclk_vio_grf to critical clock on the RK3399 Date: Tue, 14 Jun 2016 08:43:09 +0200 Message-ID: <6790996.3s1cEPUy90@diego> User-Agent: KMail/4.14.10 (Linux/4.5.0-2-amd64; KDE/4.14.14; x86_64; ; ) In-Reply-To: References: <1465724913-14553-1-git-send-email-zhengxing@rock-chips.com> <575F73B1.9000703@rock-chips.com> 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 Am Montag, 13. Juni 2016, 20:49:39 schrieb Doug Anderson: > Hi, > > On Mon, Jun 13, 2016 at 8:02 PM, Xing Zheng wrote: > > Hi Doug, > > > > On 2016年06月14日 07:46, Doug Anderson wrote: > >> Even if it's not much power, it seems like we should still turn it off > >> and on in the right place. Unless I'm mistaken it should be such a > >> simple patch provide the clock to the right driver and then get the > >> clock when appropriate. > > > > Yes, I talked with Yakir and we intent to enable/disable the pclk_vio_grf > > in video drivers, > > so this patch will be dropped. > > > >>> I will refer the latest TRM to update a new patch for always enable > >>> these > >>> GRFs. > >> > >> Does that mean you're going to make these all critical clocks? That > >> doesn't sound so great... > >> > >> -Doug > > > > Maybe, I heard that they are removed in the updated TRM, but I have not > > got > > the TRM yet. > > I will double check it, and it seems that you do not agree to remove these > > clock... > > Well, if it were to be removed from the TRM then that would be a > strong sign that the SoC designers think that this clock should never > ever be turned off. If that were the case I don't think I could > object to leaving this clock on all the time. Presumably then we'd > totally remove the clock from the clock tree and rely on firmware to > leave it on? Technically removing this clock is not really > device-tree backward compatible, but I guess if there are no current > users... > > ...note: if the clock IS listed in the TRM and there's ever a chance > that we'd want to turn it off, it's much easier to set that up all > now. Trying to later go in and decide that these clocks are no longer > "always on" gets into all sorts of weird device tree backward > compatibility corner cases. PCLK_VIO_GRF gets already exported as clock-id, so we already have the wired corner-case :-) . But we'll see how this plays out.