From patchwork Thu Dec 29 16:45:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 637704 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52A0EC4332F for ; Thu, 29 Dec 2022 16:46:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233853AbiL2QqV (ORCPT ); Thu, 29 Dec 2022 11:46:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233860AbiL2Qp5 (ORCPT ); Thu, 29 Dec 2022 11:45:57 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E526F1582F for ; Thu, 29 Dec 2022 08:45:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1672332308; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=uE1P5Bdwlwa4H9qvumuO6cO/f01N5gt3QNmApvjrJ90=; b=YbmARvYcZ31nJz+p4QCUJ8v1izr6RtFdmFDwef0tT8CSmn85lQhfEjmrtasAqsmF4pTiGh FuipnZDjb5brOaIrIToBq8OO1IHeFK3b8JYce7O18jhxp3FhS9dJ5Luqojnhy6jZYQr75H yH5YrwUQMinQIq3vBcjzObyxBhECOAQ= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-612-5iRBfx7aM--DWanDil9SkA-1; Thu, 29 Dec 2022 11:45:04 -0500 X-MC-Unique: 5iRBfx7aM--DWanDil9SkA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 0E9C4185A794; Thu, 29 Dec 2022 16:45:04 +0000 (UTC) Received: from shalem.redhat.com (unknown [10.39.192.28]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7FEAE4010D42; Thu, 29 Dec 2022 16:45:02 +0000 (UTC) From: Hans de Goede To: Bartosz Golaszewski , Bartosz Golaszewski , Linus Walleij , Dmitry Torokhov Cc: Hans de Goede , Mika Westerberg , Andy Shevchenko , "regressions @ lists . linux . dev" , linux-gpio@vger.kernel.org, linux-acpi@vger.kernel.org Subject: [PATCH 6.2 regression fix] gpiolib: Fix using uninitialized lookup-flags on ACPI platforms Date: Thu, 29 Dec 2022 17:45:01 +0100 Message-Id: <20221229164501.76044-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Commit 8eb1f71e7acc ("gpiolib: consolidate GPIO lookups") refactors fwnode_get_named_gpiod() and gpiod_get_index() into a unified gpiod_find_and_request() helper. The old functions both initialized their local lookupflags variable to GPIO_LOOKUP_FLAGS_DEFAULT, but the new code leaves it uninitialized. This is a problem for at least ACPI platforms, where acpi_find_gpio() only does a bunch of *lookupflags |= GPIO_* statements and thus relies on the variable being initialized. The variable not being initialized leads to: 1. Potentially the wrong flags getting used 2. The check for conflicting lookup flags in gpiod_configure_flags(): "multiple pull-up, pull-down or pull-disable enabled, invalid config" sometimes triggering, making the GPIO unavailable Restore the initialization of lookupflags to GPIO_LOOKUP_FLAGS_DEFAULT to fix this. Fixes: 8eb1f71e7acc ("gpiolib: consolidate GPIO lookups") Signed-off-by: Hans de Goede --- Note I'm not working and not reading work email until Monday January 9th. I hit this while doing some hobby stuff and I decided to send this out right away to avoid others potentially wasting time debugging this, but I will not see any replies until Monday January 9th. --- drivers/gpio/gpiolib.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 5a66d9616d7c..939c776b9488 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -3905,8 +3905,8 @@ static struct gpio_desc *gpiod_find_and_request(struct device *consumer, const char *label, bool platform_lookup_allowed) { + unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT; struct gpio_desc *desc = ERR_PTR(-ENOENT); - unsigned long lookupflags; int ret; if (!IS_ERR_OR_NULL(fwnode))