Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755201AbcDDLVE (ORCPT ); Mon, 4 Apr 2016 07:21:04 -0400 Received: from mail-oi0-f52.google.com ([209.85.218.52]:36019 "EHLO mail-oi0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753197AbcDDLVC (ORCPT ); Mon, 4 Apr 2016 07:21:02 -0400 MIME-Version: 1.0 In-Reply-To: <20160404014359.GA15178@leoy-linaro> References: <1459589383-16914-1-git-send-email-guodong.xu@linaro.org> <1459589383-16914-3-git-send-email-guodong.xu@linaro.org> <20160404014359.GA15178@leoy-linaro> Date: Mon, 4 Apr 2016 13:21:00 +0200 Message-ID: Subject: Re: [PATCH v2 02/16] arm64: dts: add sp804 timer node for Hi6220 From: Linus Walleij To: Leo Yan Cc: Guodong Xu , Xu Wei , Mark Rutland , Rob Herring , Grant Likely , Arnd Bergmann , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , XinWei Kong Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1205 Lines: 29 On Mon, Apr 4, 2016 at 3:43 AM, Leo Yan wrote: > On Sun, Apr 03, 2016 at 09:23:42PM +0200, Linus Walleij wrote: >> On Sat, Apr 2, 2016 at 11:29 AM, Guodong Xu wrote: >> By chance the code in the driver will allow just one clock and >> will then assume that both the bus to the timer and the timer >> itself is clocked from the same clock. But I highly doubt that this >> is the case. > > This patch has been sent out for review previously [1]; So I refered > other platforms and changed to only enable apb bus clock due I have > not found timer enabling bits in Hi6220's spec. This is not about enabling/disabling the clock(s) to the timer. It doesn't matter if these clocks are always on. It is about determining the *frequency* of the timers. It is vital that the timer driver get the right frequency of the clock to the block from the clock implementation, and I do not think it is the same as the "apb_pclk". The thing is that of course "any frequency" will work but what you will notice is that the timer runs very weirdly compared to wall-clock time unless the right clock yielding the right frequency has been specified here. Yours, Linus Walleij