Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757755AbXI2JCc (ORCPT ); Sat, 29 Sep 2007 05:02:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757315AbXI2JCL (ORCPT ); Sat, 29 Sep 2007 05:02:11 -0400 Received: from einhorn.in-berlin.de ([192.109.42.8]:50476 "EHLO einhorn.in-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757098AbXI2JCJ (ORCPT ); Sat, 29 Sep 2007 05:02:09 -0400 X-Envelope-From: stefanr@s5r6.in-berlin.de Date: Sat, 29 Sep 2007 11:01:51 +0200 (CEST) From: Stefan Richter Subject: Re: [PATCH] firewire: adopt read cycle timer ABI from raw1394 To: =?iso-8859-1?Q?Kristian_H=F8gsberg?= , Pieter Palmers cc: linux1394-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=us-ascii Content-Disposition: INLINE Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1566 Lines: 46 > This duplicates the read cycle timer feature of raw1394 (added in Linux > 2.6.21) in firewire-core's userspace ABI. Kristian and Pieter, does this simple duplication of the ioctl make sense on its own? AFAIU rawiso's iso packet buffers look different from fw-cdevs's. It seems to me as if rawiso always put the cycle into a user buffer for each iso packet received... raw1394.h::struct raw1394_iso_packet_info { __u32 offset; __u16 len; __u16 cycle; /* recv only */ __u8 channel; /* recv only */ __u8 tag; __u8 sy; }; raw1394.c::raw1394_iso_recv_packets() /* copy the packet_infos out */ for (i = 0; i < upackets.n_packets; i++) { if (__copy_to_user(&upackets.infos[i], &fi->iso_handle->infos[packet], sizeof(struct raw1394_iso_packet_info))) return -EFAULT; packet = (packet + 1) % fi->iso_handle->buf_packets; } ...while the Juju ABI returns the cycle only for those packets whose fw_cdev_iso_packet.control had the FW_CDEV_ISO_INTERRUPT flag set. The cycle is then written out in the fw_cdev_event_iso_interrupt event which happens when this particular packet was received. Right? Pieter, do applications like yours need the cycle counter only for a few predetermined packets or for each and every packet? -- Stefan Richter -=====-=-=== =--= ===-= http://arcgraph.de/sr/ - 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/