Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932924AbaGUPyx (ORCPT ); Mon, 21 Jul 2014 11:54:53 -0400 Received: from mail-yk0-f170.google.com ([209.85.160.170]:64322 "EHLO mail-yk0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932322AbaGUPyt (ORCPT ); Mon, 21 Jul 2014 11:54:49 -0400 Date: Mon, 21 Jul 2014 12:53:52 -0300 From: Ezequiel Garcia To: Felipe Balbi Cc: Lothar =?iso-8859-1?Q?Wa=DFmann?= , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, George Cherian , linux-arm-kernel@lists.infradead.org, Roger Quadros Subject: Re: [PATCH 0/9] usb: musb: several bugfixes for the musb driver Message-ID: <20140721155352.GA20226@arch.cereza> References: <1405675890-8802-1-git-send-email-LW@KARO-electronics.de> <20140718161636.GA18460@arch.cereza> <20140718165044.GA30821@saruman.home> <20140721093430.3f528cc7@ipc1.ka-ro> <20140721151140.GG6852@saruman.home> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20140721151140.GG6852@saruman.home> User-Agent: Mutt/1.5.22 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21 Jul 10:11 AM, Felipe Balbi wrote: > On Mon, Jul 21, 2014 at 09:34:30AM +0200, Lothar Wa?mann wrote: > > Hi, > > > > Felipe Balbi wrote: > > > Hi, > > > > > > On Fri, Jul 18, 2014 at 01:16:36PM -0300, Ezequiel Garcia wrote: > > > > Hi Lothar, > > > > > > > > On 18 Jul 11:31 AM, Lothar Wa?mann wrote: > > > > > The first three patches do some source code cleanup in the files that > > > > > are modified in the subsequent patches. > > > > > > > > > > > > > I've applied patches 4 and 9 on a recent -next, after fixing a conflict > > > > due to patch 3 ("usb: musb_am335x: source cleanup"): > > > > > > > > > Patch 4 carries the proper fix reported in commit: > > > > > 7adb5c876e9c ("usb: musb: Fix panic upon musb_am335x module removal") > > > > > > > > > > Patch 9 reinstates module unloading support for the musb_am335x driver > > > > > which was disabled due to a false failure analysis > > > > > > > > > > > > > For these two patches, Tested-by: Ezequiel Garcia > > > > > > > > Tested on a beaglebone with a mass storage USB device, module load/unload > > > > works without issues. The module_get/put in the phy is now preventing the > > > > musb_am335x driver unload, which seems to be the real cause of the issue > > > > I reported. Thanks for providing a proper fix! > > > > > > I don't that's a good fix. The problem is that even after am335x > > > removing all its child, someone else tried to release the PHY. That > > > ordering is the one that needs to be fixed. Doing a module_get on the > > > parent device looks like a hack to me. > > > > > No. It guarantees that the module cannot be unloaded when its resources > > are still in use! > > it's still a hack. You have a child incrementing the usage count on its > parent just because a sibbling isn't doing the right thing. > How about having the musb_am335x (glue driver) call request_module and module_get on the phy-am335x? Wouldn't this be a cleaner approach? I haven't checked if this possible, though. -- Ezequiel Garcia, VanguardiaSur www.vanguardiasur.com.ar -- 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/