From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966659AbbDVQpH (ORCPT ); Wed, 22 Apr 2015 12:45:07 -0400 Received: from mail-ie0-f177.google.com ([209.85.223.177]:36506 "EHLO mail-ie0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966100AbbDVQpC (ORCPT ); Wed, 22 Apr 2015 12:45:02 -0400 Date: Wed, 22 Apr 2015 11:44:57 -0500 From: Bjorn Helgaas To: Ricardo Ribalda Delgado Cc: Greg Kroah-Hartman , Grant Likely , Rob Herring , Andrew Morton , Jakub Sitnicki , Vivek Goyal , Jiang Liu , Mike Travis , Thierry Reding , linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v3 3/4] base/platform: Continue on insert_resource() error Message-ID: <20150422164457.GI20701@google.com> References: <1429719261-18024-1-git-send-email-ricardo.ribalda@gmail.com> <1429719261-18024-4-git-send-email-ricardo.ribalda@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1429719261-18024-4-git-send-email-ricardo.ribalda@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 22, 2015 at 06:14:20PM +0200, Ricardo Ribalda Delgado wrote: > insert_resource() can fail when the resource added overlaps > (partially or fully) with another. > > Device tree and AMBA devices may contain resources that overlap, so they > could not call platform_device_add (Revert "of: use platform_device_add" > 02bbde7849e68e193cefaa1885fe0df0f03c9fcd ) Usual style for referencing a commit is "(see 02bbde7849e6 ('Revert "of: use platform_device_add"'))". > On the other hand, device trees are released using > platform_device_unregister(). This function calls platform_device_del(), > which calls release_resource(), that crashes when the resource has not > been added with with insert_resource. This was not an issue when the > device tree could not be modified online, but this is not the case > anymore. > > This patch let the flow continue when there is an insert error, after > notifying the user with a dev_err(). r->parent is set to NULL, so the > device_del knows that the resource was not added, and therefore it > should not be released. I think you meant platform_device_del()? I don't think device_del() does anything with resources. > Signed-off-by: Ricardo Ribalda Delgado > --- > drivers/base/platform.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index 6028681..8cce2a3 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -359,8 +359,7 @@ int platform_device_add(struct platform_device *pdev) > > if (insert_resource(p, r)) { > dev_err(&pdev->dev, "failed to claim resource %d\n", i); Sounds like we should expect to see this message more in the future, after you change of_platform_device_create_pdata() use platform_device_add(). You might want to use insert_resource_conflict() here so you can include information about *why* we failed to claim the resource. And it would be nice to use %pR for both resources. > - ret = -EBUSY; > - goto failed; > + r->parent = NULL; > } > } > > @@ -371,7 +370,6 @@ int platform_device_add(struct platform_device *pdev) > if (ret == 0) > return ret; > > - failed: Might be nice to keep a comment here as a clue that the rest of the function is the failure path. It's a minor style thing, but I would also remove the "err_out" label and return "ret" directly above rather than branching to "err_out". > if (pdev->id_auto) { > ida_simple_remove(&platform_devid_ida, pdev->id); > pdev->id = PLATFORM_DEVID_AUTO; > @@ -381,7 +379,8 @@ int platform_device_add(struct platform_device *pdev) > struct resource *r = &pdev->resource[i]; > unsigned long type = resource_type(r); > > - if (type == IORESOURCE_MEM || type == IORESOURCE_IO) > + if ((type == IORESOURCE_MEM || type == IORESOURCE_IO) && > + r->parent) > release_resource(r); > } > > @@ -414,7 +413,8 @@ void platform_device_del(struct platform_device *pdev) > struct resource *r = &pdev->resource[i]; > unsigned long type = resource_type(r); > > - if (type == IORESOURCE_MEM || type == IORESOURCE_IO) > + if ((type == IORESOURCE_MEM || type == IORESOURCE_IO) && > + r->parent) > release_resource(r); > } > } > -- > 2.1.4 >