Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752479Ab0BBMBZ (ORCPT ); Tue, 2 Feb 2010 07:01:25 -0500 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:36085 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750910Ab0BBMBX (ORCPT ); Tue, 2 Feb 2010 07:01:23 -0500 Subject: Re: USB mass storage and ARM cache coherency From: Catalin Marinas To: Oliver Neukum Cc: Matthew Dharm , Sergei Shtylyov , Ming Lei , linux-usb@vger.kernel.org, linux-kernel , Sebastian Siewior , Greg KH In-Reply-To: <201002021248.10994.oliver@neukum.org> References: <20100129185434.GH19501@one-eyed-alien.net> <1265045354.25750.52.camel@pc1117.cambridge.arm.com> <201002021248.10994.oliver@neukum.org> Content-Type: text/plain Organization: ARM Ltd Date: Tue, 02 Feb 2010 12:01:12 +0000 Message-Id: <1265112072.12634.53.camel@pc1117.cambridge.arm.com> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 02 Feb 2010 12:01:13.0755 (UTC) FILETIME=[6AD0FEB0:01CAA3FF] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1104 Lines: 25 On Tue, 2010-02-02 at 11:48 +0000, Oliver Neukum wrote: > Am Montag, 1. Februar 2010 18:29:14 schrieb Catalin Marinas: > > + if (usb_pipein(urb->pipe) && usb_pipetype(urb->pipe) == PIPE_BULK) { > > + void *ptr; > > + for (ptr = urb->transfer_buffer; > > + ptr < urb->transfer_buffer + urb->transfer_buffer_length; > > + ptr += PAGE_SIZE) > > + flush_dcache_page(virt_to_page(ptr)); > > Is it correct to limit this to BULK pipes? I'm not entirely sure. The flush_dcache_page() should only be called for pages that may be mapped into user space (page cache pages). We don't need this for control buffers. It was my impression that what's coming from the mass storage layer intended for page cache pages has the PIPE_BULK type (I may be wrong though). -- Catalin -- 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/