From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from vps0.lunn.ch ([185.16.172.187]:58134 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751447AbeCNXkC (ORCPT ); Wed, 14 Mar 2018 19:40:02 -0400 Date: Thu, 15 Mar 2018 00:39:51 +0100 From: Andrew Lunn To: Vinicius Costa Gomes Cc: netdev@vger.kernel.org, randy.e.witt@intel.com, davem@davemloft.net, eric.dumazet@gmail.com Subject: Re: [PATCH net-next v2 0/2] skbuff: Fix applications not being woken for errors Message-ID: <20180314233951.GC16379@lunn.ch> References: <20180314215437.14726-1-vinicius.gomes@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180314215437.14726-1-vinicius.gomes@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Mar 14, 2018 at 02:54:35PM -0700, Vinicius Costa Gomes wrote: > Hi, > > Changes from v1: > - Fixed comments from Willem de Bruijn, about the order of the > options passed to getopt(); > - Added Reviewed-by and Fixes tags to patch (2); > > Changes from the RFC: > - tweaked commit messages; > > Original cover letter: > > This is actually a "bug report"-RFC instead of the more usual "new > feature"-RFC. > > We are developing an application that uses TX hardware timestamping to > make some measurements, and during development Randy Witt initially > reported that the application poll() never unblocked when TX hardware > timestamping was enabled. Hi Vinicius This sounds a lot like an issue i was chasing a month ago with ptp4l and the newly added PTP support for Marvell switch chips. I was seeing poll not unblocking, and when it did, the sequence numbers for PTP messages indicating they were old. But it suddenly started working, and i've not been able to reproduce it again. > (my hypothesis is that only triggers when the error is reported from > a different task context than the application). The case i was having problems with, it is a kernel task which does the error reporting, which is clearly a different context to the ptp4l application. So your hypothesis could be correct. Andrew