From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Z4MsG-0007fN-Le for barebox@lists.infradead.org; Mon, 15 Jun 2015 05:23:57 +0000 Date: Mon, 15 Jun 2015 07:23:33 +0200 From: Sascha Hauer Message-ID: <20150615052333.GK6325@pengutronix.de> References: <557AA945.4040108@celad.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <557AA945.4040108@celad.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [RFC] Barebox shutdown hooks To: Herve Codina Cc: "barebox@lists.infradead.org" Hi Herve, On Fri, Jun 12, 2015 at 11:41:25AM +0200, Herve Codina wrote: > I try to find a way to perform some tasks on barebox leaving (ie last step of go command or boot/bootm command) > and i look at shutdown_barebox (common/startup.c) > This function is : > ---- 8< ----- > void shutdown_barebox(void) > { > devices_shutdown(); > #ifdef ARCH_SHUTDOWN > arch_shutdown(); > #endif > if (board_shutdown) > board_shutdown(); > } > ---- 8< ----- > > I have several questions : > > 1) Why board_shutdown is called after arch_shutdown. > arch shutdown is supposed to do stuf like disabling mmu, flushing cache, ... > Don't you think that board_shutdown should be between devices_shutdown and arch_shutdown ? You are probably right. Only one single board implements board_shutdown anyway, so I guess it's just where it suited the original author. > > 2) What about the ability to have hooks for shutdown with all resources available > For my tasks, i need devices available. What do you thing about a new "early_shutdown" called before devices_shutdown. > barebox_shutdown will become : > void shutdown_barebox(void) > { > early_shutdown(); > devices_shutdown(); > #ifdef ARCH_SHUTDOWN > arch_shutdown(); > #endif > if (board_shutdown) > board_shutdown(); > } > > for early_shutdown itself, i would give flexibility. I thing about 2 way : > > 2.1) register shutdown hooks > Use same mechanism as fixing up device tree : > early_shutdown_register function to register hook > and iterator calling all registered hooks in early_shutdown > > 2.2) exitcall > Use same mechanism as initcall functions : > Use a specific section to store exit hooks table. A macro early_exitcall (same mechanism as xxxx_initcall macro) will be used to do this. > Iterate on each hook in this section in early_shutdown (same mechanism as initcall in start_barebox). I vote for 2.2). It has the smaller runtime overhead and we can hook the existing devices_shutdown, arch_shutdown and board_shutdown into that mechanism aswell. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox