From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 22 May 2002 01:06:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 22 May 2002 01:06:40 -0400 Received: from 12-224-36-73.client.attbi.com ([12.224.36.73]:3076 "HELO kroah.com") by vger.kernel.org with SMTP id ; Wed, 22 May 2002 01:06:40 -0400 Date: Tue, 21 May 2002 22:06:40 -0700 From: Greg KH To: "Maksim \(Max\) Krasnyanskiy" Cc: Johannes Erdfelt , linux-kernel@vger.kernel.org, linux-usb-devel@lists.sourceforge.net Subject: Re: What to do with all of the USB UHCI drivers in the kernel ? Message-ID: <20020522050640.GA646@kroah.com> In-Reply-To: <5.1.0.14.2.20020521133408.068d2ef8@mail1.qualcomm.com> <5.1.0.14.2.20020521122422.06b21188@mail1.qualcomm.com> <5.1.0.14.2.20020521122422.06b21188@mail1.qualcomm.com> <20020521195925.GA2623@kroah.com> <5.1.0.14.2.20020521133408.068d2ef8@mail1.qualcomm.com> <5.1.0.14.2.20020521164157.06b68430@mail1.qualcomm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.26i X-Operating-System: Linux 2.2.21 (i586) Reply-By: Wed, 24 Apr 2002 03:47:56 -0700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 21, 2002 at 06:04:21PM -0700, Maksim (Max) Krasnyanskiy wrote: > > >IMO, I think testing with usb-uhci.c and uhci.c is still useful, but > >testing with the -hcd variants is the most ideal since that will be the > >final code base. > > Ok. Here is feedback on 2.5.17 uhci-hcd and usb-uhci-hcd. > I did not notice any difference in behavior. Both have the same > performance, just like 2.4.19-pre8. > > One-shot interrupt transfers are broken in *-hcd drivers. core/hcd.c > returns EINVAL if urb->interval==0. > My Broadcom FW loader (uses usbdevfs) needs one-shot interrupts. So in > order to test Broadcom devices > I changed to hcd.c to allow urb->interval==0. With that change uhci-hcd > works just fine, I can load fw and > use the device. But usb-uhci-hcd kills the machine pretty hard (hw reset > needed). > > Here is a patch for hcd.c. Thanks for the patch. > On a side note. Why are URBs still not SLABified ? > Drivers still have those silly urb pools and stuff. I thought you guys were > gonna fix that. It hasn't been proven that it's really needed. 95% of the current drivers create their urbs when the device is plugged in, and then free them when they are removed. Making that kind of allocation into a slab is a bit silly :) Now if more drivers start doing fun stuff like the visor.c driver does in the 2.5 tree, then it might make more sense to create a URB specific slab. thanks, greg k-h