Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760882AbaLLGnA (ORCPT ); Fri, 12 Dec 2014 01:43:00 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51810 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758937AbaLLGQz (ORCPT ); Fri, 12 Dec 2014 01:16:55 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Benjamin Herrenschmidt" , "Grant Likely" , "Rob Herring" Date: Fri, 12 Dec 2014 06:14:25 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 135/164] of/base: Fix PowerPC address parsing hack In-Reply-To: X-SA-Exim-Connect-IP: 2001:470:1f08:1539:c97:8151:cc89:c28d X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.65-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Herrenschmidt commit 746c9e9f92dde2789908e51a354ba90a1962a2eb upstream. We have a historical hack that treats missing ranges properties as the equivalent of an empty one. This is needed for ancient PowerMac "bad" device-trees, and shouldn't be enabled for any other PowerPC platform, otherwise we get some nasty layout of devices in sysfs or even duplication when a set of otherwise identically named devices is created multiple times under a different parent node with no ranges property. This fix is needed for the PowerNV i2c busses to be exposed properly and will fix a number of other embedded cases. Signed-off-by: Benjamin Herrenschmidt Acked-by: Grant Likely Signed-off-by: Rob Herring [bwh: Backported to 3.2: use #ifdef because IS_ENABLED() only works for config symbols that are defined on the current architecture] Signed-off-by: Ben Hutchings --- drivers/of/address.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -333,6 +333,22 @@ static struct of_bus *of_match_bus(struc return NULL; } +static int of_empty_ranges_quirk(void) +{ +#ifdef CONFIG_PPC + /* To save cycles, we cache the result */ + static int quirk_state = -1; + + if (quirk_state < 0) + quirk_state = + of_machine_is_compatible("Power Macintosh") || + of_machine_is_compatible("MacRISC"); + return quirk_state; +#else + return false; +#endif +} + static int of_translate_one(struct device_node *parent, struct of_bus *bus, struct of_bus *pbus, u32 *addr, int na, int ns, int pna, const char *rprop) @@ -358,12 +374,10 @@ static int of_translate_one(struct devic * This code is only enabled on powerpc. --gcl */ ranges = of_get_property(parent, rprop, &rlen); -#if !defined(CONFIG_PPC) - if (ranges == NULL) { + if (ranges == NULL && !of_empty_ranges_quirk()) { pr_err("OF: no ranges; cannot translate\n"); return 1; } -#endif /* !defined(CONFIG_PPC) */ if (ranges == NULL || rlen == 0) { offset = of_read_number(addr, na); memset(addr, 0, pna * 4); -- 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/