Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752506Ab0HYHac (ORCPT ); Wed, 25 Aug 2010 03:30:32 -0400 Received: from mail-gx0-f174.google.com ([209.85.161.174]:43440 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751124Ab0HYHaa convert rfc822-to-8bit (ORCPT ); Wed, 25 Aug 2010 03:30:30 -0400 MIME-Version: 1.0 In-Reply-To: <1282583922-984-1-git-send-email-khilman@deeprootsystems.com> References: <1282583922-984-1-git-send-email-khilman@deeprootsystems.com> From: Grant Likely Date: Wed, 25 Aug 2010 01:30:09 -0600 X-Google-Sender-Auth: k6a6i4gzU1t5PX6myjkx-MW2UOI Message-ID: Subject: Re: [PATCH v2] driver core: platform_bus: allow runtime override of dev_pm_ops To: Kevin Hilman Cc: linux-kernel@vger.kernel.org, Magnus Damm , Greg Kroah-Hartman , =?ISO-8859-1?Q?Uwe_Kleine=2DK=F6nig?= , Paul Mundt , Magnus Damm , Eric Miao , netdev@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4217 Lines: 108 On Mon, Aug 23, 2010 at 11:18 AM, Kevin Hilman wrote: > Currently, the platform_bus allows customization of several of the > busses dev_pm_ops methods by using weak symbols so that platform code > can override them. ?The weak-symbol approach is not scalable when > wanting to support multiple platforms in a single kernel binary. > > Instead, provide __init methods for platform code to customize the > dev_pm_ops methods at runtime. > > NOTE: after these dynamic methods are merged, the weak symbols should > ? ? ?be removed from drivers/base/platform.c. ?AFAIK, this will only > ? ? ?affect SH and sh-mobile which should be converted to use this > ? ? ?runtime approach instead of the weak symbols. ?After SH & > ? ? ?sh-mobile are converted, the weak symobols could be removed. > > Tested on OMAP3. > > Cc: Grant Likely > Cc: Magnus Damm > Signed-off-by: Kevin Hilman Looks good to me. A handful of nitpicks below, I don't know if Greg will want you to respin for these or not. Feel free to add my acked-by line though: Acked-by: Grant Likely > --- > ?drivers/base/platform.c ? ? ? ? | ? 35 +++++++++++++++++++++++++++++++++++ > ?include/linux/platform_device.h | ? ?3 +++ > ?2 files changed, 38 insertions(+), 0 deletions(-) > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index c6c933f..e40a773 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -976,6 +976,41 @@ struct bus_type platform_bus_type = { > ?}; > ?EXPORT_SYMBOL_GPL(platform_bus_type); > > +/** > + * platform_bus_get_pm_ops: return pointer to busses dev_pm_ops Nit: first line of kerneldoc format should look like this: /** * platform_bus_get_pm_ops() - return pointer to busses dev_pm_ops > + * > + * This function can be used by platform code to get the current > + * set of dev_pm_ops functions used by the platform_bus_type. > + */ > +const struct dev_pm_ops * __init platform_bus_get_pm_ops(void) > +{ > + ? ? ? return platform_bus_type.pm; > +} > + > +/** > + * platform_bus_set_pm_ops: update dev_pm_ops for the platform_bus_type > + * > + * @pm: pointer to new dev_pm_ops struct to be used for platform_bus_type > + * > + * Platform code can override the dev_pm_ops methods of > + * platform_bus_type by using this function. ?It is expected that > + * platform code will first do a platform_bus_get_pm_ops(), then > + * kmemdup it, then customize selected methods and pass a pointer to > + * the new struct dev_pm_ops to this function. > + * > + * Since platform-specific code is customizing methods for *all* > + * devices (not just platform-specific devices) it is expected that > + * any custom overrides of these functions will keep existing behavior > + * and simply extend it. ?For example, any customization of the > + * runtime PM methods should continue to call the pm_generic_* > + * functions as the default ones do in addition to the > + * platform-specific behavior. > + */ > +void __init platform_bus_set_pm_ops(struct dev_pm_ops *pm) nit: const struct dev_pm_ops would be appropriate > +{ > + ? ? ? platform_bus_type.pm = pm; > +} > + > ?int __init platform_bus_init(void) > ?{ > ? ? ? ?int error; > diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h > index d7ecad0..cd55d39 100644 > --- a/include/linux/platform_device.h > +++ b/include/linux/platform_device.h > @@ -138,6 +138,9 @@ extern struct platform_device *platform_create_bundle(struct platform_driver *dr > ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?struct resource *res, unsigned int n_res, > ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?const void *data, size_t size); > > +extern const struct dev_pm_ops * __init platform_bus_get_pm_ops(void); > +extern void __init platform_bus_set_pm_ops(struct dev_pm_ops *pm); The __init annotations should only appear in the .c file, not the header. Cheers, g. -- 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/