From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 138CAC433DB for ; Wed, 10 Feb 2021 13:32:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C15E864E77 for ; Wed, 10 Feb 2021 13:32:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230328AbhBJNce (ORCPT ); Wed, 10 Feb 2021 08:32:34 -0500 Received: from cloudserver094114.home.pl ([79.96.170.134]:41634 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229789AbhBJNce (ORCPT ); Wed, 10 Feb 2021 08:32:34 -0500 Received: from localhost (127.0.0.1) (HELO v370.home.net.pl) by /usr/run/smtp (/usr/run/postfix/private/idea_smtp) via UNIX with SMTP (IdeaSmtpServer 0.83.537) id fef06e97a1c7c808; Wed, 10 Feb 2021 14:31:49 +0100 Received: from kreacher.localnet (89-64-80-225.dynamic.chello.pl [89.64.80.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by v370.home.net.pl (Postfix) with ESMTPSA id E0A5E6608FC; Wed, 10 Feb 2021 14:31:48 +0100 (CET) From: "Rafael J. Wysocki" To: Andy Shevchenko Cc: "Rafael J. Wysocki" , ACPI Devel Maling List , Linux Kernel Mailing List , Len Brown , Calvin Johnson Subject: Re: [PATCH v1 7/7] ACPI: property: Allow counting a single value as an array of 1 element Date: Wed, 10 Feb 2021 14:31:48 +0100 Message-ID: <3881654.NPl3a4M0kB@kreacher> In-Reply-To: References: <20210210114320.3478-1-andriy.shevchenko@linux.intel.com> <20210210114320.3478-7-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-VADE-SPAMSTATE: clean X-VADE-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduledrheejgdehfecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfjqffogffrnfdpggftiffpkfenuceurghilhhouhhtmecuudehtdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvufffkfgjfhgggfgtsehtufertddttddvnecuhfhrohhmpedftfgrfhgrvghlucflrdcuhgihshhotghkihdfuceorhhjfiesrhhjfiihshhotghkihdrnhgvtheqnecuggftrfgrthhtvghrnhepgfelheffhfetffelhfelteejffetteetgfetkeejvdfhfeeftdeufeevgeevieevnecukfhppeekledrieegrdektddrvddvheenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpeekledrieegrdektddrvddvhedphhgvlhhopehkrhgvrggthhgvrhdrlhhotggrlhhnvghtpdhmrghilhhfrhhomhepfdftrghfrggvlhculfdrucghhihsohgtkhhifdcuoehrjhifsehrjhifhihsohgtkhhirdhnvghtqedprhgtphhtthhopegrnhgurhhihidrshhhvghvtghhvghnkhhosehlihhnuhigrdhinhhtvghlrdgtohhmpdhrtghpthhtoheprhgrfhgrvghlsehkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqdgrtghpihesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehlvghnsgeskhgvrhhnvghl rdhorhhgpdhrtghpthhtoheptggrlhhvihhnrdhjohhhnhhsohhnsehoshhsrdhngihprdgtohhm X-DCC--Metrics: v370.home.net.pl 1024; Body=6 Fuz1=6 Fuz2=6 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Wednesday, February 10, 2021 1:36:00 PM CET Rafael J. Wysocki wrote: > On Wed, Feb 10, 2021 at 12:51 PM Andy Shevchenko > wrote: > > > > We allow to read the single value as a first element in the array. > > Unfortunately the counting doesn't work in this case and we can't > > call fwnode_property_count_*() API without getting an error. > > It would be good to mention what the symptom of the issue is here. > > > Modify acpi_data_prop_read() to always try the single value read > > and thus allow counting the single value as an array of 1 element. > > > > Reported-by: Calvin Johnson > > Signed-off-by: Andy Shevchenko > > This is a bug fix, so it should go in before the cleanups in this series IMO. > > Also it looks like stable@vger material. > > > --- > > drivers/acpi/property.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c > > index 236316ee0e25..d6100585fceb 100644 > > --- a/drivers/acpi/property.c > > +++ b/drivers/acpi/property.c > > @@ -913,12 +913,14 @@ static int acpi_data_prop_read(const struct acpi_device_data *data, > > const union acpi_object *items; > > int ret; > > > > - if (val && nval == 1) { > > + /* Try to read as a single value first */ > > + if (!val || nval == 1) { > > ret = acpi_data_prop_read_single(data, propname, proptype, val); > > This returns -EINVAL if val is NULL. > > > if (ret >= 0) > > - return ret; > > + return val ? ret : 1; > > So val cannot be NULL here. > > > } > > > > + /* It's not the single value, get an array instead */ > > ret = acpi_data_get_property_array(data, propname, ACPI_TYPE_ANY, &obj); > > if (ret) > > return ret; > > -- > > To me, acpi_fwnode_property_read_string_array() needs to special-case > val == NULL and nval == 0. Well, scratch this. Something like the patch below (untested) should be sufficient to address this if I'm not mistaken. --- drivers/acpi/property.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) Index: linux-pm/drivers/acpi/property.c =================================================================== --- linux-pm.orig/drivers/acpi/property.c +++ linux-pm/drivers/acpi/property.c @@ -787,14 +787,14 @@ static int acpi_data_prop_read_single(co const union acpi_object *obj; int ret; - if (!val) - return -EINVAL; - if (proptype >= DEV_PROP_U8 && proptype <= DEV_PROP_U64) { ret = acpi_data_get_property(data, propname, ACPI_TYPE_INTEGER, &obj); if (ret) return ret; + if (!val) + return 1; + switch (proptype) { case DEV_PROP_U8: if (obj->integer.value > U8_MAX) @@ -820,7 +820,8 @@ static int acpi_data_prop_read_single(co if (ret) return ret; - *(char **)val = obj->string.pointer; + if (val) + *(char **)val = obj->string.pointer; return 1; } else { @@ -928,10 +929,16 @@ static int acpi_data_prop_read(const str const union acpi_object *items; int ret; - if (val && nval == 1) { + if (nval == 1) { ret = acpi_data_prop_read_single(data, propname, proptype, val); if (ret >= 0) return ret; + + /* + * Reading this property as a single-value one failed, but its + * value may still be represented as one-element array, so + * continue. + */ } ret = acpi_data_get_property_array(data, propname, ACPI_TYPE_ANY, &obj);