From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751892Ab1ITUYS (ORCPT ); Tue, 20 Sep 2011 16:24:18 -0400 Received: from mail-gx0-f174.google.com ([209.85.161.174]:57918 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750763Ab1ITUYQ (ORCPT ); Tue, 20 Sep 2011 16:24:16 -0400 From: Rob Herring To: linux-arm-kernel@lists.infradead.org, devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org Cc: grant.likely@secretlab.ca, marc.zyngier@arm.com, thomas.abraham@linaro.org, jamie@jamieiles.com, b-cousson@ti.com, shawn.guo@linaro.org, dave.martin@linaro.org, linux@arm.linux.org.uk, Rob Herring Subject: [PATCH 1/3] of/irq: of_irq_find_parent: check for parent equal to child Date: Tue, 20 Sep 2011 15:24:02 -0500 Message-Id: <1316550244-3655-2-git-send-email-robherring2@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1316550244-3655-1-git-send-email-robherring2@gmail.com> References: <1316550244-3655-1-git-send-email-robherring2@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rob Herring An interrupt controller may often implicitly inherit itself from a parent node when in fact the controller is the interrupt root controller. Guard against the case of child == parent and return NULL in this case. This can also be fixed by adding an explicit "interrupt-parent;" to a root interrupt controller node. Based on code from Grant Likely. Signed-off-by: Rob Herring Cc: Grant Likely --- drivers/of/irq.c | 14 +++++++------- 1 files changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/of/irq.c b/drivers/of/irq.c index 9f689f1..6a5b5e7 100644 --- a/drivers/of/irq.c +++ b/drivers/of/irq.c @@ -58,27 +58,27 @@ EXPORT_SYMBOL_GPL(irq_of_parse_and_map); */ struct device_node *of_irq_find_parent(struct device_node *child) { - struct device_node *p; + struct device_node *p, *c = child; const __be32 *parp; - if (!of_node_get(child)) + if (!of_node_get(c)) return NULL; do { - parp = of_get_property(child, "interrupt-parent", NULL); + parp = of_get_property(c, "interrupt-parent", NULL); if (parp == NULL) - p = of_get_parent(child); + p = of_get_parent(c); else { if (of_irq_workarounds & OF_IMAP_NO_PHANDLE) p = of_node_get(of_irq_dflt_pic); else p = of_find_node_by_phandle(be32_to_cpup(parp)); } - of_node_put(child); - child = p; + of_node_put(c); + c = p; } while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL); - return p; + return (p == child) ? NULL : p; } /** -- 1.7.5.4