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 14:58:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 22 May 2002 14:58:18 -0400 Received: from [129.46.51.59] ([129.46.51.59]:36844 "EHLO ithilien.qualcomm.com") by vger.kernel.org with ESMTP id ; Wed, 22 May 2002 14:58:16 -0400 Message-Id: <5.1.0.14.2.20020522103053.07be5808@mail1.qualcomm.com> X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Wed, 22 May 2002 11:57:40 -0700 To: David Brownell From: "Maksim (Max) Krasnyanskiy" Subject: Re: [linux-usb-devel] Re: What to do with all of the USB UHCI drivers in the kernel ? Cc: linux-kernel@vger.kernel.org, linux-usb-devel@lists.sourceforge.net In-Reply-To: <3CEB1F7F.4000000@pacbell.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org At 09:33 PM 5/21/2002 -0700, David Brownell wrote: >Maksim (Max) Krasnyanskiy wrote: >>One-shot interrupt transfers are broken in *-hcd drivers. core/hcd.c >>returns EINVAL if urb->interval==0. ><....> >Meanwhile, I suppose I can see wanting access to that UHCI-ism. >However your patch would do that wrong, since it should only >apply to interrupt transfers. Yeah, I guess it doesn't make sense to do one-shot iso. >>On a side note. Why are URBs still not SLABified ? > >Hasn't seemed to be necessary. kmalloc() is slabified already, >so it's not clear that a control/bulk/interrupt URB pool shared >between drivers -- size, maybe a handful -- would be better than >sharing that same memory with other kernel code. Well, kmalloc has slabs of a fixed size and will round requested amount to the nearest value. For example on x86 sizeof(struct urb) == 84 which will be rounded to 96 by kmalloc ie 12 bytes unused (on Sparc64 it's about 20 bytes). Also we could use slab constructor to pre-initialize some urb fields. Max