From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johan Hovold Date: Mon, 23 Sep 2013 15:20:18 +0000 Subject: Re: [PATCH 0/7] driver core: prevent deferred probe with platform_driver_probe Message-Id: <20130923152018.GB1454@localhost> List-Id: References: <20130923134028.GF21013@sirena.org.uk> <1379946452-25649-1-git-send-email-jhovold@gmail.com> <20130923145029.GV30088@pengutronix.de> In-Reply-To: <20130923145029.GV30088@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Sascha Hauer Cc: Johan Hovold , Greg Kroah-Hartman , Grant Likely , Mark Brown , linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mtd@lists.infradead.org, linux-pcmcia@lists.infradead.org, linux-usb@vger.kernel.org, linux-fbdev@vger.kernel.org On Mon, Sep 23, 2013 at 04:50:29PM +0200, Sascha Hauer wrote: > On Mon, Sep 23, 2013 at 04:27:25PM +0200, Johan Hovold wrote: > > Deferred probing cannot be used with platform_driver_probe as by the > > time probing is retried either the driver has been unregistered or its > > probe function has been set to platform_drv_probe_fail. > > > > With commit e9354576 ("gpiolib: Defer failed gpio requests by default") > > the gpio subsystem started returning -EPROBE_DEFER, which in turn > > several platform drivers using platform_driver_probe return to driver > > core. Other subsystems (e.g. regulator) has since started doing the > > same. > > > > The first patch in this series prevents platform drivers using > > platform_driver_probe from requesting probe deferral while warning that > > it is not supported. > > > > The remaining patches move six platform-driver probe functions that rely > > on gpio_request out of __init. There are likely other probe functions > > that might return -EPROBE_DEFER and should be moved out of __init as > > well. > > As usually when I read this I wonder why platform_driver_probe exists > anyway. The only advantage I can think off is that the probe functions > are in __init and thus can be disposed of later. Now you remove the > __init annotations from these probe functions. Wouldn't it be better to > convert the drivers to regular platform_driver_register instead? Perhaps that paragraph was a bit unclear: I move them out of __init _and_ use platform_driver_register instead of platform_driver_probe as well. Johan