From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v4] mmc: Add ioctl to let userspace apps send ACMDs Date: Mon, 18 Apr 2011 16:42:48 +0200 Message-ID: <201104181642.48742.arnd@arndb.de> References: <201104130110.46815.arnd@arndb.de> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from moutng.kundenserver.de ([212.227.17.9]:56471 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753258Ab1DROm4 (ORCPT ); Mon, 18 Apr 2011 10:42:56 -0400 In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: John Calixto Cc: linux-mmc@vger.kernel.org, =?utf-8?q?Micha=C5=82_Miros=C5=82aw?= , Chris Ball , Andrei Warkentin On Wednesday 13 April 2011, John Calixto wrote: > > Since the code is limited to ACMD and cannot do arbitrary commands, it's actually > > not possible to use this for the passthrough scenario, so you should not mention > > it in the changelog. > > > > I would also still advocate something more high-level here because it's limited > > to a single use case. If you make the ioctl interface do the security commands > > directly, you would not need to rely on CAP_SYS_RAWIO. > > > > I'm happy to remove the text about passthrough from the changelog, but > it is a valid use for this ioctl. I agree that ACMD by itself is not > sufficient for full passthrough, but this patch is a starting point for > anyone wanting to implement full CMD passthrough. > > There are also several ACMD opcodes that are not related to security, > but to functionality like requesting to change the signalling voltage, > setting bus width, setting pre-erase block count, etc... I think those > commands are what caused others to request some kind of capability > restriction. > Ok, I see. In v6, it seems you have implemented the full CMD passthrough, if I read it correctly. Is there anything still missing? Arnd