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Lukas Wunner 3e81a4ca51 Bluetooth: hci_bcm: Mandate presence of shutdown and device wake GPIO
Commit 0395ffc1ee ("Bluetooth: hci_bcm: Add PM for BCM devices")
amended this driver to request a shutdown and device wake GPIO on probe,
but mandated that only one of them need to be present:

	/* Make sure at-least one of the GPIO is defined and that
	 * a name is specified for this instance
	 */
	if ((!dev->device_wakeup && !dev->shutdown) || !dev->name) {
		dev_err(&pdev->dev, "invalid platform data\n");
		return -EINVAL;
	}

However the same commit added a call to bcm_gpio_set_power() to the
->probe hook, which unconditionally accesses *both* GPIOs.  Luckily,
the resulting NULL pointer deref was never reported, suggesting there's
no machine where either GPIO is missing.

Commit 8a92056837 ("Bluetooth: hci_bcm: Add (runtime)pm support to the
serdev driver") removed the check whether at least one of the GPIOs is
present without specifying a reason.

Because commit 62aaefa7d0 ("Bluetooth: hci_bcm: improve use of gpios
API") refactored the driver to use devm_gpiod_get_optional() instead of
devm_gpiod_get(), one is now tempted to believe that the driver doesn't
require *any* of the two GPIOs.

Which is wrong, the driver still requires both GPIOs to avoid a NULL
pointer deref.  To this end, establish the status quo ante and request
the GPIOs with devm_gpiod_get() again.  Bail out of ->probe if either
of them is missing.

Oddly enough, whereas bcm_gpio_set_power() accesses the device wake pin
unconditionally, bcm_suspend_device() and bcm_resume_device() do check
for its presence before accessing it.  Those checks are superfluous,
so remove them.

Cc: Frédéric Danis <frederic.danis.oss@gmail.com>
Cc: Loic Poulain <loic.poulain@linaro.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2018-01-10 19:00:12 +01:00
Documentation dt-bindings: net: mediatek: add condition to property mediatek, pctl 2017-12-26 12:05:45 -05:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-12-22 11:16:31 -05:00
block block-throttle: avoid double charge 2017-12-20 11:10:17 -07:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-12-11 16:32:45 -08:00
drivers Bluetooth: hci_bcm: Mandate presence of shutdown and device wake GPIO 2018-01-10 19:00:12 +01:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-12-22 11:16:31 -05:00
include rtnetlink: Replace implementation of ASSERT_RTNL() macro with WARN_ONCE() 2017-12-26 12:30:02 -05:00
init main: kernel_start: move housekeeping_init() before workqueue_init_early() 2017-11-27 08:56:57 -08:00
ipc Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-12-22 11:16:31 -05:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-12-22 11:16:31 -05:00
mm Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2017-12-21 11:13:37 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-12-22 11:16:31 -05:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2017-12-18 10:51:06 -05:00
scripts Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-12-15 11:44:59 -08:00
security Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-12-16 22:11:55 -05:00
sound sound fixes for 4.15-rc5 2017-12-20 13:03:20 -08:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-12-22 11:16:31 -05:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt KVM/ARM Fixes for v4.15, Round 2 2017-12-18 12:57:43 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild misc updates for v4.15 2017-11-17 17:51:33 -08:00
.mailmap Add Jason Gunthorpe as co-maintainer of the RDMA stack 2017-11-17 09:36:18 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS batman-adv: Convert packet.h to uapi header 2017-12-21 15:35:53 -05:00
Makefile Linux 4.15-rc4 2017-12-17 18:59:59 -08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.