Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758173Ab3CUNKk (ORCPT ); Thu, 21 Mar 2013 09:10:40 -0400 Received: from mail-ob0-f175.google.com ([209.85.214.175]:43300 "EHLO mail-ob0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756333Ab3CUNKh (ORCPT ); Thu, 21 Mar 2013 09:10:37 -0400 MIME-Version: 1.0 In-Reply-To: <201303201146.07987.arnd@arndb.de> References: <1363266691-15757-1-git-send-email-fabio.porcedda@gmail.com> <201303201020.14654.arnd@arndb.de> <201303201146.07987.arnd@arndb.de> From: Fabio Porcedda Date: Thu, 21 Mar 2013 14:10:17 +0100 Message-ID: Subject: Re: [PATCH 10/10] drivers: misc: use module_platform_driver_probe() To: Arnd Bergmann Cc: Geert Uytterhoeven , H Hartley Sweeten , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-media@vger.kernel.org" , "linux-ide@vger.kernel.org" , "lm-sensors@lm-sensors.org" , "linux-input@vger.kernel.org" , "linux-fbdev@vger.kernel.org" , Greg Kroah-Hartman , Grant Likely 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: 1845 Lines: 50 On Wed, Mar 20, 2013 at 12:46 PM, Arnd Bergmann wrote: > On Wednesday 20 March 2013, Fabio Porcedda wrote: >> >> On Wed, Mar 20, 2013 at 11:20 AM, Arnd Bergmann wrote: >> > On Wednesday 20 March 2013, Fabio Porcedda wrote: >> >> I think we can check inside the deferred_probe_work_func() >> >> if the dev->probe function pointer is equal to platform_drv_probe_fail(). >> > >> > I think it's too late by then, because that would only warn if we try to probe >> > it again, but when platform_driver_probe() does not succeed immediately, it >> >> Maybe you mean "does succeed immediately" ? > > I mean in this code (simplified for the sake of discussion) > > int __init_or_module platform_driver_probe(struct platform_driver *drv, > int (*probe)(struct platform_device *)) > { > int retval, code; > > drv->probe = probe; > retval = code = platform_driver_register(drv); > > drv->probe = NULL; > if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list)) > retval = -ENODEV; > drv->driver.probe = platform_drv_probe_fail; > > if (code != retval) > platform_driver_unregister(drv); > return retval; > } > > we assume that all devices are bound to drivers during the call to > platform_driver_register, and if the device list is empty afterwards, > we unregister the driver and will never get to the deferred probing > stage. Thanks for the explanation, I understand now that is not that simple. I was hoping it was easier. Regards -- Fabio Porcedda -- 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/