On Tue, Jul 19, 2011 at 08:48:41AM +0100, Russell King - ARM Linux wrote: > On Tue, Jul 19, 2011 at 09:17:26AM +0800, Shawn Guo wrote: > > On Mon, Jul 18, 2011 at 10:02:44AM -0700, Dmitry Torokhov wrote: > > > On Monday, July 18, 2011 09:45:07 AM Shawn Guo wrote: > > > > The patch makes a copy of platform data into driver data, so that any > > > > reference to platform_data after .probe exits can be avoided. > > > > > > And why is this beneficial? I am of the opinion that platform data should > > > stay on (and be accessed through a const pointer to ensure that the driver > > > will not alter it). > > > > > To me, it's a common sense that platform data should not be referenced > > after .probe exits, so that any platform code providing the data can > > claim the data as __initconst. > > That's totally buggered, and that's putting it kindly. > Well, you can tell I'm an idiot, but I was not trying to do what you say here. > Consider a driver built as a module, vs built-in. If you build it as a > module, your driver data is stale by the time you insert the module. > It's not much better with it built-in - if you have hotplug enabled, you > can unbind and rebind the driver, which means that the .probe function > can be called long after the .init sections have been discarded. > > So no, this is no justification for the patch. > > Don't *ever* make any platform devices or any data pointed to by a > platform device discardable after init time. It's an oops waiting to > happen. > Something learnt. Thanks, Russell. -- Regards, Shawn -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
