From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH resend] Renesas Ethernet AVB driver Date: Tue, 14 Apr 2015 19:58:18 +0300 Message-ID: <552D472A.6080309@cogentembedded.com> References: <2926619.fiYHPz1IBk@wasted.cogentembedded.com> <20150328082853.GA4255@localhost.localdomain> <5519D380.6070200@cogentembedded.com> <552C25BE.3070606@cogentembedded.com> <20150414052729.GA5179@netboy> <552CE890.3040103@cogentembedded.com> <20150414163002.GB4309@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, devicetree@vger.kernel.org, galak@codeaurora.org, netdev@vger.kernel.org, linux-sh@vger.kernel.org, Mitsuhiro Kimura , masaru.nagai.vx@renesas.com To: Richard Cochran Return-path: Received: from mail-la0-f42.google.com ([209.85.215.42]:35701 "EHLO mail-la0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933002AbbDNQ6X (ORCPT ); Tue, 14 Apr 2015 12:58:23 -0400 Received: by labbd9 with SMTP id bd9so13139287lab.2 for ; Tue, 14 Apr 2015 09:58:21 -0700 (PDT) In-Reply-To: <20150414163002.GB4309@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-ID: Hello. On 04/14/2015 07:30 PM, Richard Cochran wrote: >>> It is surely avoidable. The driver knows (or should know) whether or >>> not the hardware has been configured or not. >> So you only want to avoid the register read here? > No, that is not what I mean. The two callers are gettime and adjtime. > Can't you make sure the hardware is ready before you register the I tried to explain to you that I can't. We enter the device configuration mode (from the operation mode) when e.g. the *Ethernet* device is closed. > clock in the first place? If not, what is purpose of returning EBUSY? I'm not sure (remember, I'm not the primary author), perhaps this is to prevent bad time values when the AVB-DMAC in not operational... Nagai-san, could you explain this please? > Thanks, > Richard WBR, Sergei