Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932670AbaBABB5 (ORCPT ); Fri, 31 Jan 2014 20:01:57 -0500 Received: from quartz.orcorp.ca ([184.70.90.242]:49593 "EHLO quartz.orcorp.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754343AbaBABB4 (ORCPT ); Fri, 31 Jan 2014 20:01:56 -0500 Date: Fri, 31 Jan 2014 18:01:50 -0700 From: Jason Gunthorpe To: Florian Fainelli Cc: Rob Herring , Grant Likely , "linux-kernel@vger.kernel.org" , netdev Subject: Re: [PATCH 2/2] of_mdio: Allow the DT to specify the phy ID and avoid autoprobing Message-ID: <20140201010150.GB2519@obsidianresearch.com> References: <1391205045-1751-1-git-send-email-jgunthorpe@obsidianresearch.com> <1391205045-1751-2-git-send-email-jgunthorpe@obsidianresearch.com> <20140131225513.GA2519@obsidianresearch.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Broken-Reverse-DNS: no host name found for IP address 10.0.0.161 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 31, 2014 at 03:28:10PM -0800, Florian Fainelli wrote: > - you tell of_mdiobus_register() to look for a reset phandle and have > a reset controller release the PHY from reset before it tries to probe > for it, because doing that could avoid doing the PHY out of reset > sequence in a few dozen Ethernet drivers I think this would be interesting, but difficult. Ideally you'd want to keep the phy in reset until an ethernet driver attaches to it, and reset it again once it detaches, so Linux would have to defer probing the phy driver until an attach. Not sure what this would do for power consumption, but reset might be lower power on phy's that don't have an internal power down. > The auto-probing bypass logic looks simple enough, and it does not > require burying the reset logic behind a reset controller, which > uses Right, it closely matches what was happening in board files. FWIW, this system was designed in 2005 for Linux 2.16 and this patch set fell out of porting forward to 3.13 w/ DT. Jason -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/