Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752186AbbKJU1E (ORCPT ); Tue, 10 Nov 2015 15:27:04 -0500 Received: from mail-wm0-f49.google.com ([74.125.82.49]:36017 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751691AbbKJU1B (ORCPT ); Tue, 10 Nov 2015 15:27:01 -0500 MIME-Version: 1.0 In-Reply-To: <20151110194938.GA47666@tevye.fc.hp.com> References: <5411049831df211c8280e3239aaf344af033fa25.1446684001.git.jerry.hoemann@hpe.com> <20151110194938.GA47666@tevye.fc.hp.com> Date: Tue, 10 Nov 2015 12:27:00 -0800 Message-ID: Subject: Re: [PATCH 1/4] nvdimm: Add wrapper for IOCTL pass thru. From: Dan Williams To: Jerry Hoemann Cc: Jeff Moyer , Ross Zwisler , "Rafael J. Wysocki" , Len Brown , Linux ACPI , "linux-kernel@vger.kernel.org" , linux-nvdimm Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1445 Lines: 29 On Tue, Nov 10, 2015 at 11:49 AM, Jerry Hoemann wrote: > On Tue, Nov 10, 2015 at 12:51:59PM -0500, Jeff Moyer wrote: >> Jerry Hoemann writes: >> >> > Add IOCTL type 'P' to denote NVDIMM_TYPE_PASSTHRU. >> >> Can't you just make passthrough a separate command? If you actually add > > There are multiple conflicting NVDIMM _DSM running around, they > are "device specific". So, we should plan in general and not just > for the example DSM that Intel added support for. These DSM have > over lapping and incompatible function ids. > > The Intel example is an example, not standard. They are free to > change it at will. So, we can't be certain there won't be a > conflict some time in the future if we try to use their number space. > > I'm trying to create a generic pass thru that any vendors can use. Putting > this in the Intel function number space doesn't make a lot of sense to me. It isn't the "Intel" function number space. The fact that they currently align is just a happy accident. The kernel is free to break the 1:1 ioctl number to DSM function number relationship, and I think it would make the implementation cleaner in this case. -- 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/