From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Cochran Subject: Re: [PATCH net-next RFC 0/9] net: dsa: PTP timestamping for mv88e6xxx Date: Fri, 29 Sep 2017 05:43:23 -0400 Message-ID: <20170929094323.cwh2ubv4odknlyot@localhost> References: <1506612341-18061-1-git-send-email-brandon.streiff@ni.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "David S. Miller" , Florian Fainelli , Andrew Lunn , Vivien Didelot , Erik Hons To: Brandon Streiff Return-path: Content-Disposition: inline In-Reply-To: <1506612341-18061-1-git-send-email-brandon.streiff@ni.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Brandon, On Thu, Sep 28, 2017 at 10:25:32AM -0500, Brandon Streiff wrote: > - Patch #2: We expose the switch time as a PTP clock but don't support > adjustment (max_adj=0). The driver should implement a cyclecounter/timecounter. > Our platform adjusted a systemwide oscillator > from userspace, so we didn't need adjustment at this layer, but other > PTP clock drivers support this and we probably should too. We don't currently have any way to support this kind of HW or anything like an external VCO. I would like to find a way to do this, but that is a different kettle of fish as it might require changes in the PHC subsystem. For this driver, I think we should get it merged using the cyclecounter/timecounter (as that will benefit lots of users) and worry about the external oscillator later. > Feedback is appreciated. I happy to see this series. I just finished porting an out-of-tree PHC driver for the Marvell mv88e635x, and I want to mainline it, but I also have a few uglies. Unfortunately I am in the middle of a move right now, and so my review of this series might have to wait a bit. However, I am looking forward to comparing notes, and then getting this support in. Thanks, Richard