Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754640Ab2KIQxw (ORCPT ); Fri, 9 Nov 2012 11:53:52 -0500 Received: from mail-wi0-f178.google.com ([209.85.212.178]:52730 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754270Ab2KIQxs (ORCPT ); Fri, 9 Nov 2012 11:53:48 -0500 MIME-Version: 1.0 In-Reply-To: References: <1351928793-14375-1-git-send-email-mika.westerberg@linux.intel.com> <3455360.Z6cZSC3BtR@vostro.rjw.lan> <1523215.Pon1eKPQDb@vostro.rjw.lan> <20121107095608.GX24532@intel.com> <20121108200445.GC16012@intel.com> From: Bjorn Helgaas Date: Fri, 9 Nov 2012 09:53:26 -0700 Message-ID: Subject: Re: [PATCH 2/3] spi / ACPI: add ACPI enumeration support To: Grant Likely Cc: Mika Westerberg , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, lenb@kernel.org, rafael.j.wysocki@intel.com, broonie@opensource.wolfsonmicro.com, linus.walleij@linaro.org, khali@linux-fr.org, ben-linux@fluff.org, w.sang@pengutronix.de, mathias.nyman@linux.intel.com, linux-acpi@vger.kernel.org, Greg Kroah-Hartman , "H. Peter Anvin" , Tony Luck Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2579 Lines: 52 On Fri, Nov 9, 2012 at 9:43 AM, Grant Likely wrote: > On Fri, Nov 9, 2012 at 4:35 PM, Bjorn Helgaas wrote: >> On Fri, Nov 9, 2012 at 8:45 AM, Grant Likely wrote: >>> On Fri, Nov 9, 2012 at 3:11 PM, Bjorn Helgaas wrote: >>>> [+cc Greg, Peter, Tony since they acked the original patch [1]] >>>> >>>> On Thu, Nov 8, 2012 at 1:04 PM, Mika Westerberg >>>> wrote: >>>>> On Thu, Nov 08, 2012 at 12:32:25PM -0700, Bjorn Helgaas wrote: >>>>>> Struct device_driver is a generic structure, so it seems strange to >>>>>> have to include non-generic things like of_device_id and now >>>>>> acpi_match_table there. >>>>> >>>>> Yes, but in a sense the DT and ACPI are "generic". So that they are used to >>>>> describe the configuration of a machine. >>>> >>>> What I meant by "generic" was "useful across all architectures." The >>>> new acpi_match_table and acpi_handle fields [1] are not generic in >>>> that sense because they're present on all architectures but used only >>>> on x86 and ia64. The existing of_match_table and of_node are >>>> similarly unused on many architectures. This doesn't seem like a >>>> scalable strategy to me. Are we going to add a pnpbios_node for x86 >>>> PNPBIOS machines without ACPI, a pdc_hpa for parisc machines with PDC, >>>> etc.? >>>> >>>> [1] https://patchwork.kernel.org/patch/1677221/ >>> >>> Ultimately yes, I think that is what we want to do, >> >> Just to be clear, you think we *should* add things like pnpbios_node, >> pdc_hpa, etc., to struct device, one field for every scheme of telling >> the OS about non-enumerable devices, where only one of the N fields is >> used on any given machine? That seems surprising to me, but maybe I >> just need to be educated :) > > Ah, I see what you're asking. > > In the short term, yes but only because we don't have any other > alternative. What I'd really rather have is a safe way to attach datum > (ie. acpi_device or device_node) to a struct device and get it back > later in a type safe way. Yep, *that* makes perfect sense to me. Something along these lines, maybe: #define dev_is_acpi(d) ((d)->bus == &acpi_bus_type) #define dev_acpi_handle(d) (dev_is_acpi(d) ? (acpi_handle) d->datum : NULL) -- 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/