Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757825Ab3CSJEg (ORCPT ); Tue, 19 Mar 2013 05:04:36 -0400 Received: from mail-ia0-f170.google.com ([209.85.210.170]:47199 "EHLO mail-ia0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754788Ab3CSJEd (ORCPT ); Tue, 19 Mar 2013 05:04:33 -0400 MIME-Version: 1.0 In-Reply-To: References: <1363266691-15757-1-git-send-email-fabio.porcedda@gmail.com> <201303181058.51641.arnd@arndb.de> <201303181128.45215.arnd@arndb.de> Date: Tue, 19 Mar 2013 10:04:32 +0100 X-Google-Sender-Auth: T5yuHLgO8-IYjR2X8VK1HbbZwR0 Message-ID: Subject: Re: [PATCH 10/10] drivers: misc: use module_platform_driver_probe() From: Geert Uytterhoeven To: Fabio Porcedda , Arnd Bergmann Cc: 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 , Hans-Christian Egtvedt , Grant Likely Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2098 Lines: 49 On Tue, Mar 19, 2013 at 9:55 AM, Fabio Porcedda wrote: > On Mon, Mar 18, 2013 at 12:28 PM, Arnd Bergmann wrote: >> On Monday 18 March 2013, Fabio Porcedda wrote: >>> On Mon, Mar 18, 2013 at 11:58 AM, Arnd Bergmann wrote: >>> > On Monday 18 March 2013, Fabio Porcedda wrote: >>> >> Since by using platform_driver_probe() the function >>> >> ep93xx_pwm_probe() is freed after initialization, >>> >> is better to use module_platform_drive_probe(). >>> >> IMHO i don't see any good reason to use module_platform_driver() for >>> >> this driver. >>> > >>> > As I commented earlier, the platform_driver_probe() and >>> > module_platform_drive_probe() interfaces are rather dangerous in combination >>> > with deferred probing, I would much prefer Harley's patch. >>> >>> Since those drivers don't use -EPROBE_DEFER i was thinking that they don't use >>> deferred probing. >>> I'm missing something? >> >> clk_get() may return -EPROBE_DEFER after ep93xx is converted to use the >> common clk API. We currently return the value of clk_get from the probe() >> function, which will automatically do the right thing as long as the probe >> function remains reachable. > > Thanks for the explanation. Hmm, so we may have drivers that (now) work perfectly fine with module_platform_driver_probe()/platform_driver_probe(), but will start failing suddenly in the future? I guess we need a big fat WARN_ON(-EPROBE_DEFER) in platform_driver_probe() to catch these? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- 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/