From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 86724C072B5 for ; Fri, 24 May 2019 05:48:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4360F21855 for ; Fri, 24 May 2019 05:48:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558676925; bh=kniP8lflxSW1ANVxsn0GMckkxNtkCWcdW66EPGHbMf4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ORcQLcppPG0HOrgTKyDukJ9K2Mtj312tvqUsr7nQygqKJg/N318iFsbekBJB5RviS /ShcD6RiOr7s0D3RmIKmdaoPBEGtFsGQ6PyzkaOcq8L4sD6lkWtlk8V+PwLJAQOwrL CFhbyCBkvSTPTkASShj9mUb6goCJsAweRl6+UOqM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388195AbfEXFso (ORCPT ); Fri, 24 May 2019 01:48:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:36842 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387535AbfEXFso (ORCPT ); Fri, 24 May 2019 01:48:44 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1C8822168B; Fri, 24 May 2019 05:48:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558676922; bh=kniP8lflxSW1ANVxsn0GMckkxNtkCWcdW66EPGHbMf4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BmoqDFbULhReo/Tswv/s2XraivvkocEHWYQtFwk85z8Bd6iwt6cEFUb5iM8YSUfXz 96/jVjz1HgBQgfSihTAFvrnxmvuvy+uyY5sklyZSUXYNdsUWBssHvOtcR6MDvwh9lM Ek7lQD9fk5PE5OEWKuqHpfE0y4KEflu+mjM/UQMw= Date: Fri, 24 May 2019 07:48:40 +0200 From: Greg Kroah-Hartman To: Saravana Kannan Cc: Rob Herring , Mark Rutland , "Rafael J. Wysocki" , Frank Rowand , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH v1 5/5] driver core: Add sync_state driver/bus callback Message-ID: <20190524054840.GB31664@kroah.com> References: <20190524010117.225219-1-saravanak@google.com> <20190524010117.225219-6-saravanak@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190524010117.225219-6-saravanak@google.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 23, 2019 at 06:01:16PM -0700, Saravana Kannan wrote: > This sync_state driver/bus callback is called once all the consumers > of a supplier have probed successfully. > > This allows the supplier device's driver/bus to sync the supplier > device's state to the software state with the guarantee that all the > consumers are actively managing the resources provided by the supplier > device. > > To maintain backwards compatibility and ease transition from existing > frameworks and resource cleanup schemes, late_initcall_sync is the > earliest when the sync_state callback might be called. > > There is no upper bound on the time by which the sync_state callback > has to be called. This is because if a consumer device never probes, > the supplier has to maintain its resources in the state left by the > bootloader. For example, if the bootloader leaves the display > backlight at a fixed voltage and the backlight driver is never probed, > you don't want the backlight to ever be turned off after boot up. > > Signed-off-by: Saravana Kannan > --- > drivers/base/core.c | 39 +++++++++++++++++++++++++++++++++++++++ > drivers/of/platform.c | 9 +++++++++ > include/linux/device.h | 19 +++++++++++++++++++ > 3 files changed, 67 insertions(+) Also: Reviewed-by: Greg Kroah-Hartman thanks, greg k-h