Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932417Ab0KNXY3 (ORCPT ); Sun, 14 Nov 2010 18:24:29 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51377 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755284Ab0KNXY1 convert rfc822-to-8bit (ORCPT ); Sun, 14 Nov 2010 18:24:27 -0500 Date: Sun, 14 Nov 2010 16:25:02 -0700 From: Pete Zaitcev To: =?UTF-8?B?TsOpbWV0aCBNw6FydG9u?= Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, LKML , zaitcev@redhat.com Subject: Re: [PATCH, RFC] usbmon: correct computing of the ISO packets with mmap Message-ID: <20101114162502.6d6318e7@lembas.zaitcev.lan> In-Reply-To: <4CE0458E.9070900@freemail.hu> References: <4CD8ECE4.1090206@freemail.hu> <20101109075056.59a2e7d8@lembas.zaitcev.lan> <4CD9A96D.1010306@freemail.hu> <4CDF0DF4.4020405@freemail.hu> <20101114124035.6a0c9b80@lembas.zaitcev.lan> <4CE0458E.9070900@freemail.hu> Organization: Red Hat, Inc. Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2709 Lines: 82 On Sun, 14 Nov 2010 21:24:46 +0100 Németh Márton wrote: > Sure, I'm happy as long as I can capture the whole data content of the ISO > packets. Great. So, what do you think about the attached? It differs from your code in one important aspect: output buffer sizes are not adjusted. Your patch attempts that, but uses actual_length, which is not defined during submission events. So I skipped that. -- Pete diff --git a/drivers/usb/mon/mon_bin.c b/drivers/usb/mon/mon_bin.c index 44cb37b..15c5e46 100644 --- a/drivers/usb/mon/mon_bin.c +++ b/drivers/usb/mon/mon_bin.c @@ -437,6 +437,28 @@ static unsigned int mon_bin_get_data(const struct mon_reader_bin *rp, return length; } +/* + * This is the look-ahead pass in case of 'Ci', when actual_length cannot + * be used to determine the length of the whole contiguous buffer. + */ +static unsigned int mon_bin_collate_isodesc(const struct mon_reader_bin *rp, + struct urb *urb, unsigned int ndesc) +{ + struct usb_iso_packet_descriptor *fp; + unsigned int length; + + length = 0; + fp = urb->iso_frame_desc; + while (ndesc-- != 0) { + if (fp->status == 0 && fp->actual_length != 0) { + if (fp->offset + fp->actual_length > length) + length = fp->offset + fp->actual_length; + } + fp++; + } + return length; +} + static void mon_bin_get_isodesc(const struct mon_reader_bin *rp, unsigned int offset, struct urb *urb, char ev_type, unsigned int ndesc) { @@ -479,6 +501,10 @@ static void mon_bin_event(struct mon_reader_bin *rp, struct urb *urb, /* * Find the maximum allowable length, then allocate space. */ + urb_length = (ev_type == 'S') ? + urb->transfer_buffer_length : urb->actual_length; + length = urb_length; + if (usb_endpoint_xfer_isoc(epd)) { if (urb->number_of_packets < 0) { ndesc = 0; @@ -487,14 +513,16 @@ static void mon_bin_event(struct mon_reader_bin *rp, struct urb *urb, } else { ndesc = urb->number_of_packets; } + if (ev_type == 'C' && usb_urb_dir_in(urb)) + length = mon_bin_collate_isodesc(rp, urb, ndesc); } else { ndesc = 0; } lendesc = ndesc*sizeof(struct mon_bin_isodesc); - urb_length = (ev_type == 'S') ? - urb->transfer_buffer_length : urb->actual_length; - length = urb_length; + /* not an issue unless there's a subtle bug in a HCD somewhere */ + if (length >= urb->transfer_buffer_length) + length = urb->transfer_buffer_length; if (length >= rp->b_size/5) length = rp->b_size/5; -- 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/