This is a note to let you know that I've just added the patch titled
Bluetooth: hci_bcm: Mandate presence of shutdown and device wake GPIO
to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bluetooth-hci_bcm-mandate-presence-of-shutdown-and-device-wake-gpio.patch
and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Mon Apr 9 10:16:32 CEST 2018
From: Lukas Wunner <lukas@xxxxxxxxx>
Date: Wed, 10 Jan 2018 16:32:10 +0100
Subject: Bluetooth: hci_bcm: Mandate presence of shutdown and device wake GPIO
From: Lukas Wunner <lukas@xxxxxxxxx>
[ Upstream commit 3e81a4ca51a1172253078ca7abd6a91040b8fcf4 ]
Commit 0395ffc1ee05 ("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 8a92056837fd ("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 62aaefa7d038 ("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@xxxxxxxxx>
Cc: Loic Poulain <loic.poulain@xxxxxxxxxx>
Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
Cc: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/bluetooth/hci_bcm.c | 24 +++++++++---------------
1 file changed, 9 insertions(+), 15 deletions(-)
--- a/drivers/bluetooth/hci_bcm.c
+++ b/drivers/bluetooth/hci_bcm.c
@@ -577,11 +577,9 @@ static int bcm_suspend_device(struct dev
}
/* Suspend the device */
- if (bdev->device_wakeup) {
- gpiod_set_value(bdev->device_wakeup, false);
- bt_dev_dbg(bdev, "suspend, delaying 15 ms");
- mdelay(15);
- }
+ gpiod_set_value(bdev->device_wakeup, false);
+ bt_dev_dbg(bdev, "suspend, delaying 15 ms");
+ mdelay(15);
return 0;
}
@@ -592,11 +590,9 @@ static int bcm_resume_device(struct devi
bt_dev_dbg(bdev, "");
- if (bdev->device_wakeup) {
- gpiod_set_value(bdev->device_wakeup, true);
- bt_dev_dbg(bdev, "resume, delaying 15 ms");
- mdelay(15);
- }
+ gpiod_set_value(bdev->device_wakeup, true);
+ bt_dev_dbg(bdev, "resume, delaying 15 ms");
+ mdelay(15);
/* When this executes, the device has woken up already */
if (bdev->is_suspended && bdev->hu) {
@@ -779,14 +775,12 @@ static int bcm_get_resources(struct bcm_
dev->clk = devm_clk_get(dev->dev, NULL);
- dev->device_wakeup = devm_gpiod_get_optional(dev->dev,
- "device-wakeup",
- GPIOD_OUT_LOW);
+ dev->device_wakeup = devm_gpiod_get(dev->dev, "device-wakeup",
+ GPIOD_OUT_LOW);
if (IS_ERR(dev->device_wakeup))
return PTR_ERR(dev->device_wakeup);
- dev->shutdown = devm_gpiod_get_optional(dev->dev, "shutdown",
- GPIOD_OUT_LOW);
+ dev->shutdown = devm_gpiod_get(dev->dev, "shutdown", GPIOD_OUT_LOW);
if (IS_ERR(dev->shutdown))
return PTR_ERR(dev->shutdown);
Patches currently in stable-queue which might be from lukas@xxxxxxxxx are
queue-4.15/bluetooth-hci_bcm-mandate-presence-of-shutdown-and-device-wake-gpio.patch
queue-4.15/bluetooth-hci_bcm-validate-irq-before-using-it.patch