From: Lukas Wunner Date: Wed, 10 Jan 2018 15:32:10 +0000 (+0100) Subject: Bluetooth: hci_bcm: Mandate presence of shutdown and device wake GPIO X-Git-Tag: for-linus-20180210~31^2~177^2~12 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=3e81a4ca51a1172253078ca7abd6a91040b8fcf4;p=linux-block.git Bluetooth: hci_bcm: Mandate presence of shutdown and device wake GPIO 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 Cc: Loic Poulain Cc: Hans de Goede Cc: Uwe Kleine-König Cc: Linus Walleij Reviewed-by: Andy Shevchenko Signed-off-by: Lukas Wunner Signed-off-by: Marcel Holtmann --- diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c index 1fc604a0d870..7d059b35c63a 100644 --- a/drivers/bluetooth/hci_bcm.c +++ b/drivers/bluetooth/hci_bcm.c @@ -572,11 +572,9 @@ static int bcm_suspend_device(struct device *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; } @@ -587,11 +585,9 @@ static int bcm_resume_device(struct device *dev) 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) { @@ -774,14 +770,12 @@ static int bcm_get_resources(struct bcm_device *dev) 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);