From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: Re: BUG?: VIA IDE transfer-rate problem Date: Tue, 17 Jan 2006 14:17:30 +0100 Message-ID: <58cb370e0601170517v6fe68992ma5bdc67d5eb1e6f1@mail.gmail.com> References: <200601131909.07981.pvrusb2@toplitzer.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from uproxy.gmail.com ([66.249.92.194]:49396 "EHLO uproxy.gmail.com") by vger.kernel.org with ESMTP id S932327AbWAQNRd convert rfc822-to-8bit (ORCPT ); Tue, 17 Jan 2006 08:17:33 -0500 Received: by uproxy.gmail.com with SMTP id s2so1059993uge for ; Tue, 17 Jan 2006 05:17:31 -0800 (PST) In-Reply-To: <200601131909.07981.pvrusb2@toplitzer.net> Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Helmut Toplitzer Cc: linux-ide@vger.kernel.org, dbrownell@users.sourceforge.net, linux-usb-devel@lists.sourceforge.net On 1/13/06, Helmut Toplitzer wrote: > > Hi! Hi, > I've got a question about a small experiment I made: > I tried to find out the transfer-rate of my hd by useing > hdparm -t /dev/hda > and got changing transferrates starting from > > 37MB/s with CPU not utilized > 55MB/s with CPU 100% utilized I can't reproduce this locally, please send me your kernel config. Although I have Intel chipset it is still worth a try if it is generic kernel bug. I don't remember seeing anything like that on my old VIA system which also had VT8235 southbridge - if somebody has similar machine to Helmut's please try to reproduce this behavior (thanks!). > 22MB/s with ehci-hcd loaded and a device already initilized > 55MB/s with ehci-hcd loaded and CPU 100% utilized > (see log1/log2) As discussed in this thread: http://marc.theaimsgroup.com/?l=linux-kernel&m=111765523627674&w=2 It seems that the problem is caused by flakey USB chipset thus IDE folks cannot do much about it, sorry. David, can we get this issue documented somewhere? > So is this supposed normal operation? Or is there > something wrong with it? > Even tried useing the lirc_dev and lirc_i2c kernel-modules > from the lirc project (Infrared remote over usb) and got > only 12MB/s on hda until using CPU with 100%. also seems like USB caused problem > So it looks like CPU/USB/IDE is in some interaction. Any > ideas what to do against this. My current kernel is > 2.6.15 Bartlomiej