Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750907AbVJAXvz (ORCPT ); Sat, 1 Oct 2005 19:51:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750909AbVJAXvz (ORCPT ); Sat, 1 Oct 2005 19:51:55 -0400 Received: from rwcrmhc13.comcast.net ([204.127.198.39]:1424 "EHLO rwcrmhc12.comcast.net") by vger.kernel.org with ESMTP id S1750907AbVJAXvz (ORCPT ); Sat, 1 Oct 2005 19:51:55 -0400 Date: Sat, 1 Oct 2005 16:20:59 -0400 From: Christopher Li To: linux-usb-devel@lists.sourceforge.net Cc: linux kernel mail list Subject: [PATCH] incrase usbdevfs bulk buffer size Message-ID: <20051001202059.GE3453@64m.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1301 Lines: 31 Increase the usbdevfs buffer size limit. I hit this limit with running ehci in the VM. The a single ehci qTD transfer buffer can be 5 pages long, that is 20K. The current devio bulk transfer limit is 16K. I am not sure why the bulk transfer limit is 16K. I can complicate the user space part to work around that, but it seems much simpler just allow usbdevfs to accept bigger buffers. I did some limited usage test with ehci controller. It seems works for me, it did use a bigger buffer and nothing blow up. Signed-Off-By: Christopher Li Index: linux-2.6.13.2/drivers/usb/core/devio.c =================================================================== --- linux-2.6.13.2.orig/drivers/usb/core/devio.c 2005-09-28 13:08:10.000000000 -0700 +++ linux-2.6.13.2/drivers/usb/core/devio.c 2005-10-01 04:58:47.000000000 -0700 @@ -72,7 +72,7 @@ MODULE_PARM_DESC (usbfs_snoop, "true to } while (0) -#define MAX_USBFS_BUFFER_SIZE 16384 +#define MAX_USBFS_BUFFER_SIZE (32*1024) static inline int connected (struct usb_device *dev) { - 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/