From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthieu CASTET Subject: Re: Problem with non aligned DMA in usbnet on ARM Date: Thu, 12 Aug 2010 19:01:20 +0200 Message-ID: <4C6428E0.8040402@parrot.com> References: <20100811095454.GA22543@n2100.arm.linux.org.uk> <20100811150443.GB8867@kroah.com> <20100811174238.GA12382@kroah.com> <4C62F4EF.1050808@gmail.com> <20100811201332.GB10379@kroah.com> <4C6324B2.2080606@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Greg KH , Russell King - ARM Linux , linux-usb , "netdev@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , To: "mfuzzey@gmail.com" Return-path: Received: from co202.xi-lite.net ([149.6.83.202]:45117 "EHLO co202.xi-lite.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750855Ab0HLRB0 (ORCPT ); Thu, 12 Aug 2010 13:01:26 -0400 In-Reply-To: <4C6324B2.2080606@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: Martin Fuzzey a =E9crit : > Greg KH wrote: >> Can you fix this in the host controller driver? >> >> =20 > Technically yes (by copying the unaligned buffers). >=20 > But if we do decide that USB must support unaligned buffers wouldn't = it > be better to have the HCD indicate it's alignment requirement to the > core and have the core do the copying? >=20 > Gary King sent a message to this thread but only to the arm list sayi= ng > he has the same problem with the tegra hcd (which doesn't seem to be = in > the tree yet.) I don't know if any of the other in tree HCDs have th= is > problem. dwc otg also got this limitation. I don't know if the version submitted= =20 for inclusion handle unaligned buffers. Matthieu