Return-path: Received: from mu-out-0910.google.com ([209.85.134.185]:56674 "EHLO mu-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751854AbXLWVST (ORCPT ); Sun, 23 Dec 2007 16:18:19 -0500 Received: by mu-out-0910.google.com with SMTP id i10so1129096mue.5 for ; Sun, 23 Dec 2007 13:18:17 -0800 (PST) To: Mattias Nissler Subject: Re: tx_status reporting of RTS/CTS frames Date: Sun, 23 Dec 2007 22:18:42 +0100 Cc: Johannes Berg , rt2400-devel , linux-wireless , Stefano Brivio References: <1197412922.7030.11.camel@localhost> <1197545672.6558.238.camel@johannes.berg> <1197572204.7489.7.camel@localhost> In-Reply-To: <1197572204.7489.7.camel@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Message-Id: <200712232218.42415.IvDoorn@gmail.com> (sfid-20071223_211821_568748_8063DC91) From: Ivo van Doorn Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thursday 13 December 2007, Mattias Nissler wrote: > > On Thu, 2007-12-13 at 12:34 +0100, Johannes Berg wrote: > > > rt2x00 devices have some flags in the TX descriptor that basically tell > > > the device to send a burst of frames, optionally requesting to wait for > > > an ack (i.e. CTS in the case of an RTS frame) for any of them. > > > > Interesting. I can't the place where that is set though, can you point > > me to it? > > For each frame, rt2x00 creates a txdata_entry_desc structure (see > rt2x00lib_write_tx_desc()), which holds all the information that is > written to the actual tx descriptors (format of these varies among the > different devices we support, but the information in the tx descriptors > is roughly the same). See rt61pci_write_tx_desc() for an example of how > the information is stored into the actual tx descriptor, but that's > rather boring. > > The bits you're interested in are ENTRY_TXD_ACK and ENTRY_TXD_BURST. > BURST tells the device the next frame is part of the same burst (also > note that we have to set the correct IFS), i.e. the next frame goes out > directly after the current one (respecting the IFS of course). The > TXD_ACK bit means the hardware should wait for an ack of some kind (e.g. > CTS for RTS frames). Additionally there is the ENTRY_TXD_RTS_FRAME flag to indicate the frame is a rts frame. This is something that at least rt2400pci and rt2500pci required for rts frames in the TX queue. Ivo