From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-qy0-f174.google.com ([209.85.216.174]:54622 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754947Ab1DKVgl convert rfc822-to-8bit (ORCPT ); Mon, 11 Apr 2011 17:36:41 -0400 MIME-Version: 1.0 In-Reply-To: <20110411212513.GA17809@kroah.com> References: <1302557114-7880-1-git-send-email-zajec5@gmail.com> <20110411210631.GA28559@kroah.com> <20110411212513.GA17809@kroah.com> Date: Mon, 11 Apr 2011 23:36:39 +0200 Message-ID: Subject: Re: [RFC][PATCH V3] axi: add AXI bus driver From: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= To: Greg KH Cc: linux-wireless@vger.kernel.org, "John W. Linville" , George Kashperko , Arnd Bergmann , Russell King , "linux-kernel@vger.kernel.org" , b43-dev@lists.infradead.org, =?UTF-8?Q?Michael_B=C3=BCsch?= , linuxdriverproject , Andy Botting , "linux-arm-kernel@lists.infradead.org" , Larry Finger Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: 2011/4/11 Greg KH : > On Mon, Apr 11, 2011 at 11:19:13PM +0200, Rafał Miłecki wrote: >> 2011/4/11 Greg KH : >> > On Mon, Apr 11, 2011 at 11:25:14PM +0200, Rafał Miłecki wrote: >> >> +static void axi_release_core_dev(struct device *dev) >> >> +{ >> >> +     /* Silent lack-of-release warning */ >> >> +} >> > >> > Ok, WTF!!!! >> >> Thank you for your kindly words. It's much more enjoyable to work on >> kernel that way. I definitely made that on purpose. > > I can't tell if you are kidding or not. That was 100% irony. I swear I don't enjoy publishing bad code and getting such a comment. > Please read the documentation for how to do this properly.  I find it > really hard to believe that you wrote that comment instead of putting in > the 2 lines of code required for this function. > > Especially as-it-is, your code does not work properly and leaks memory > badly.  Why would you do that on purpose? I tried to read some documentation about this. 1) driver-mode/device.txt says only that: > Callback to free the device after all references have > gone away. This should be set by the allocator of the > device (i.e. the bus driver that discovered the device). I *really* do not know how my driver should "free" core on AXI bus. 2) LDD3 says: > The method is called when the last reference to the device is removed; it is called > from the embedded kobject’s release method. All device structures registered with > the core must have a release method, or the kernel prints out scary complaints. Well, I do not register any structs for AXI core. 3) Example code from LDD3: static void ldd_bus_release(struct device *dev) { printk(KERN_DEBUG "lddbus release\n"); } Yeah, that's what I did... 4) SSB in it's ssb_release_dev just calls kfree on struct that was allocated when registering drivers. *I do not* allocate such a struct, so I believe I do exactly the same memory leak as SSB does. Can you spend 2 more minues in addition to commenting my ideas and help me with writing that 2 lines I missed? Where do I leak memory in my driver? Which struct should I kfree? -- Rafał