From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1D058C8CE; Wed, 11 Jun 2025 01:23:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749605031; cv=none; b=uPBmNZJYcElOeiy2P6jSiaa8f2PrvsvEN8x5uPCKvHS0OqI16+5QG2MGQ/CcC4qfH8PlCcelCOaHApPrk1qmEsmddrdhuaby+U9pI2khlkh4flOGFn+e43G/vY7a0ZzFTe/XdNJVPnVkVnHrTKsceHpTPfaQxKjY8ZnqH+ueCfo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749605031; c=relaxed/simple; bh=BDCf9UbwdWpGMgZtYBVVj+5jW5/DNFofhldRk0JItWY=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Z63j+7JXNkke70wTr8+BLYyqitFXIBVkLVPa6OQqldsxwTZy39oWUCLGrL+GmNHlHWkC1NgUmhzKnYkwuJgsquK04DIHmUcmVKspaiHoaOLGsLVK/a46F4G6EzrxxHWZ9/rQcJsAY+TT0BDkQnz4qdM2+LvL3mZNBq7d3IWZB4w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CQ28WDl6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="CQ28WDl6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C532DC4CEED; Wed, 11 Jun 2025 01:23:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749605030; bh=BDCf9UbwdWpGMgZtYBVVj+5jW5/DNFofhldRk0JItWY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=CQ28WDl6A/e3hLBO5F7mI0CtoH36tVgmSSRBc4XsJPXGCrK5iRlsUWndw/plqw4SR 9Ilmbvh0+zUoCdpTSihvL47h8JWecyb+Jd/98Ox7vuVe5ohuMR6/ect+uGzX/5dumH 3qyrQuegAev8p75VURnnE6TOA8Mr8ZaIDgfyS0Mt9iRnQkoxPhyBTlwK5JUQwEa5t0 iu2U5ERIaZx4phsCmlEx841570CRDbkMPEEJddcwvCidmIBKWoyp8uiJ60Z9F4fMEc fnZGDCQV4cYdUkp12BSIR1lrtduslfs1OoQTOcidWTBe5/Romup04eA3rkL1MBvVFl OJZILGwtZ3tDQ== Date: Tue, 10 Jun 2025 18:23:48 -0700 From: Jakub Kicinski To: Harshitha Ramamurthy Cc: netdev@vger.kernel.org, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, jeroendb@google.com, andrew+netdev@lunn.ch, willemb@google.com, ziweixiao@google.com, pkaligineedi@google.com, yyd@google.com, joshwash@google.com, shailend@google.com, linux@treblig.org, thostet@google.com, jfraker@google.com, richardcochran@gmail.com, jdamato@fastly.com, vadim.fedorenko@linux.dev, horms@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next v4 0/8] gve: Add Rx HW timestamping support Message-ID: <20250610182348.03069023@kernel.org> In-Reply-To: <20250609184029.2634345-1-hramamurthy@google.com> References: <20250609184029.2634345-1-hramamurthy@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 9 Jun 2025 18:40:21 +0000 Harshitha Ramamurthy wrote: > This patch series add the support of Rx HW timestamping, which sends > adminq commands periodically to the device for clock synchronization with > the nic. IIUC: - the driver will only register the PHC if timestamping is enabled (and unregister it when disabled), - there is no way to read the PHC from user space other than via packet timestamps, - the ethtool API does not report which PHC is associated with the NIC, presumably because the PHC is useless to the user space. Do I understand that correctly? It's pretty unusual. Why not let user read the clock? Why unregister the PHC? I understand that you may want to cancel the quite aggressive timestamp refresh work, but why kill the whole clock... Perhaps ptp_cancel_worker_sync() didn't exist when you wrote this code?