From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756066Ab0JOCP4 (ORCPT ); Thu, 14 Oct 2010 22:15:56 -0400 Received: from mail.windriver.com ([147.11.1.11]:43677 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755195Ab0JOCPy (ORCPT ); Thu, 14 Oct 2010 22:15:54 -0400 Date: Fri, 15 Oct 2010 10:15:46 +0800 From: Yong Zhang To: Tom Brown Cc: LKML Subject: Re: Question: how to copy to user space from a tasklet Message-ID: <20101015021546.GA15339@windriver.com> Reply-To: Yong Zhang References: <4CB6DEC4.4040408@cyconix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <4CB6DEC4.4040408@cyconix.com> User-Agent: Mutt/1.5.20 (2009-06-14) X-OriginalArrivalTime: 15 Oct 2010 02:15:48.0245 (UTC) FILETIME=[E1B7C450:01CB6C0E] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 14, 2010 at 11:43:16AM +0100, Tom Brown wrote: > [Sorry to have to ask this here - I can't find any driver-specific > newsgroup or mailing lists - are there any??] > > I have a driver which needs to copy device data direct to user space > from a tasklet. I need to do this because the device is continuously > DMA'ing into user space, with no user intervention, so the user > isn't waiting for data. In other words, I don't have any > user-associated process to wake up. > > This means that I have to somehow copy the data directly to the user > from the tasklet, without sleeping, and without direct access to > user context. Can someone tell me how to do this? Are you seeking for probe_kernel_read/write(include/linux/uaccess.h)? Thanks, Yong > > Thanks > > Tom > -- > 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/