From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Calixto Subject: Re: [PATCH v6] mmc: Add mmc CMD+ACMD passthrough ioctl Date: Wed, 20 Apr 2011 13:47:16 -0700 (PDT) Message-ID: References: <201104202117.14463.arnd@arndb.de> Mime-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="-1463811328-1404909235-1303332444=:28361" Return-path: Received: from elasmtp-dupuy.atl.sa.earthlink.net ([209.86.89.62]:50895 "EHLO elasmtp-dupuy.atl.sa.earthlink.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752225Ab1DTUr1 (ORCPT ); Wed, 20 Apr 2011 16:47:27 -0400 In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Chris Ball Cc: =?ISO-8859-2?Q?Micha=B3_Miros=B3aw?= , Arnd Bergmann , linux-mmc@vger.kernel.org, Andrei Warkentin This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. ---1463811328-1404909235-1303332444=:28361 Content-Type: TEXT/PLAIN; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE On Wed, 20 Apr 2011, Micha=C5=82 Miros=C5=82aw wrote: > >> I'm okay with the anon union + ``compat_ptr(*(u32 *))`` part of your > >> solution. =C2=A0If everyone else thinks it is reasonable, I'll submit = a v7 > >> with it. > > No need for a union or a ptr_size member in the struct. Just use > > a single __u64 and let the user cast the pointer to that. This > > will work on all architectures. >=20 > Union is just hiding this cast (it will be done in kernel) and allows > cleaner code for userspace (there's a single kernel and possibly > multiple applications that will implement this call). >=20 Chris, Do you have a preference here? I do not have a preference. On the one hand, not having the union makes for a cleaner-to-read struct. On the other hand, not having to cast the pointer in 32-bit userspace is nice especially since I foresee using this ioctl on a lot of ARM SoCs. John ---1463811328-1404909235-1303332444=:28361--