Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752482Ab3HBNdr (ORCPT ); Fri, 2 Aug 2013 09:33:47 -0400 Received: from hydra.sisk.pl ([212.160.235.94]:52098 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751729Ab3HBNdq (ORCPT ); Fri, 2 Aug 2013 09:33:46 -0400 From: "Rafael J. Wysocki" To: Lan Tianyu Cc: ACPI Devel Maling List , LKML , Bjorn Helgaas , Toshi Kani Subject: Re: [PATCH] ACPI: Do not fail acpi_bind_one() if device is already bound correctly Date: Fri, 02 Aug 2013 15:43:58 +0200 Message-ID: <2560973.EJVuxm6PHt@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.10.0+; KDE/4.9.5; x86_64; ; ) In-Reply-To: References: <1888947.F5IBMfDKlY@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5281 Lines: 157 On Friday, August 02, 2013 10:48:49 AM Lan Tianyu wrote: > 2013/8/2 Rafael J. Wysocki : > > From: Rafael J. Wysocki > > > > Modify acpi_bind_one() so that it doesn't fail if the device > > represented by its first argument has already been bound to the > > given ACPI handle (second argument), because that is not a good > > enough reason for returning an error code. > > > > Signed-off-by: Rafael J. Wysocki > > --- > > drivers/acpi/glue.c | 15 +++++++++++---- > > 1 file changed, 11 insertions(+), 4 deletions(-) > > > > Index: linux-pm/drivers/acpi/glue.c > > =================================================================== > > --- linux-pm.orig/drivers/acpi/glue.c > > +++ linux-pm/drivers/acpi/glue.c > > @@ -143,7 +143,10 @@ int acpi_bind_one(struct device *dev, ac > > list_for_each_entry(pn, &acpi_dev->physical_node_list, node) > > if (pn->dev == dev) { > > dev_warn(dev, "Already associated with ACPI node\n"); > > - goto err_free; > > + if (ACPI_HANDLE(dev) == handle) > > + retval = 0; > > + > > + goto out_free; > > } > > > > /* allocate physical node id according to physical_node_id_bitmap */ > > @@ -152,7 +155,7 @@ int acpi_bind_one(struct device *dev, ac > > ACPI_MAX_PHYSICAL_NODE); > > if (physical_node->node_id >= ACPI_MAX_PHYSICAL_NODE) { > > retval = -ENOSPC; > > - goto err_free; > > + goto out_free; > > } > > > > set_bit(physical_node->node_id, acpi_dev->physical_node_id_bitmap); > > @@ -185,10 +188,14 @@ int acpi_bind_one(struct device *dev, ac > > put_device(dev); > > return retval; > > > > - err_free: > > + out_free: > > mutex_unlock(&acpi_dev->physical_node_lock); > > kfree(physical_node); > > - goto err; > > + if (retval) > > + goto err; > > + > > + put_device(dev); > > + return 0; > > } > > EXPORT_SYMBOL_GPL(acpi_bind_one); > > Hi Rafael: > How about the following change? It is incorrect, because the "problem" it attempts to "fix" is actually intentional behavior. [And you could ask if it was intentional in the first place instead of assuming that it was a mistake. It wasn't.] Do you have any problems with my $subject patch? Rafael > > diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c > index f70cc45..35f375e 100644 > --- a/drivers/acpi/glue.c > +++ b/drivers/acpi/glue.c > @@ -183,19 +183,15 @@ int acpi_bind_one(struct device *dev, acpi_handle handle) > > return 0; > > - err: > - ACPI_HANDLE_SET(dev, NULL); > - put_device(dev); > - return retval; > - > out_free: > mutex_unlock(&acpi_dev->physical_node_lock); > kfree(physical_node); > - if (retval) > - goto err; > > + err: > + if (retval) > + ACPI_HANDLE_SET(dev, NULL); > put_device(dev); > - return 0; > + return retval; > } > EXPORT_SYMBOL_GPL(acpi_bind_one); > --------------- > > When I reviewed this patch, found the dev's acpi handle always > is set to NULL if there is error. This seems make no sense for > the case that the handle has been set to dev before binding. > > For this case, the acpi handle has been found before binding. > Actually, the device driver could control any resources under ACPI > node even if the binding failed. So adding one flag to differentiate > it. > > diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c > index 35f375e..c868e51 100644 > --- a/drivers/acpi/glue.c > +++ b/drivers/acpi/glue.c > @@ -113,6 +113,7 @@ int acpi_bind_one(struct device *dev, acpi_handle handle) > acpi_status status; > struct acpi_device_physical_node *physical_node, *pn; > char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2]; > + bool has_handle = false; > int retval = -EINVAL; > > if (ACPI_HANDLE(dev)) { > @@ -121,6 +122,7 @@ int acpi_bind_one(struct device *dev, acpi_handle handle) > return -EINVAL; > } else { > handle = ACPI_HANDLE(dev); > + has_handle = true; > } > } > if (!handle) > @@ -188,7 +190,7 @@ int acpi_bind_one(struct device *dev, acpi_handle handle) > kfree(physical_node); > > err: > - if (retval) > + if (retval && !has_handle) > ACPI_HANDLE_SET(dev, NULL); > put_device(dev); > return retval; > > > > > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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/