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Mon, 12 Jan 2026 20:21:32 -0800 (PST) Date: Mon, 12 Jan 2026 20:21:29 -0800 From: Richard Cochran To: Wen Gu Cc: Thomas Gleixner , "netdev@vger.kernel.org" , LKML , Jakub Kicinski , Dust Li , Xuan Zhuo , Andrew Lunn , David Woodhouse , virtualization@lists.linux.dev, Nick Shi , Sven Schnelle , Paolo Abeni , linux-clk@vger.kernel.org Subject: Re: [RFC] Defining a home/maintenance model for non-NIC PHC devices using the /dev/ptpX API Message-ID: References: <0afe19db-9c7f-4228-9fc2-f7b34c4bc227@linux.alibaba.com> Precedence: bulk X-Mailing-List: linux-clk@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0afe19db-9c7f-4228-9fc2-f7b34c4bc227@linux.alibaba.com> On Fri, Jan 09, 2026 at 10:56:56AM +0800, Wen Gu wrote: > Introducing a new clock type or a new userspace API (e.g. /dev/XXX) would > require widespread userspace changes, duplicated tooling, and long-term > fragmentation. This RFC is explicitly NOT proposing a new userspace API. Actually I disagree. The PHC devices appear to user space as clockid_t. The API for these works seamlessly and interchangeably with SYS-V clock IDs. The path that is opened, whether /dev/ptpX or some new /dev/hwclkX etc is a trivial detail that adds no burden to user space. Thanks, Richard