Hi Fred,
> Adds autosuspend runtime functionality to BCM UART driver.
> Autosuspend is enabled at end of bcm_setup.
>
> Change some CONFIG_PM_SLEEP to CONFIG_PM as hu and is_suspended parameters
> are used during runtime PM callbacks.
I think we should do that in a separate patch to prepare for the change.
> Replace SpinLock by Mutex to be able to use it in sleepable context.
> Add a work queue to be able to perform pm_runtime commands during bcm_recv
> which is called by hci_uart_tty_receive() under spinlock.
>
> Signed-off-by: Frederic Danis <frederic.danis@xxxxxxxxxxxxxxx>
> ---
> drivers/bluetooth/hci_bcm.c | 210 +++++++++++++++++++++++++++++++++-----------
> 1 file changed, 158 insertions(+), 52 deletions(-)
>
> diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
> index 1440a56..488c812 100644
> --- a/drivers/bluetooth/hci_bcm.c
> +++ b/drivers/bluetooth/hci_bcm.c
> @@ -32,6 +32,7 @@
> #include <linux/gpio/consumer.h>
> #include <linux/tty.h>
> #include <linux/interrupt.h>
> +#include <linux/pm_runtime.h>
>
> #include <net/bluetooth/bluetooth.h>
> #include <net/bluetooth/hci_core.h>
> @@ -42,6 +43,8 @@
> #define BCM_NO_FIX 0
> #define BCM_FIX_ACPI_IRQ 1
>
> +#define BCM_AUTOSUSPEND_DELAY 5000 /* default autosleep delay */
> +
> struct bcm_device {
> struct list_head list;
>
> @@ -57,7 +60,7 @@ struct bcm_device {
>
> u32 init_speed;
>
> -#ifdef CONFIG_PM_SLEEP
> +#ifdef CONFIG_PM
> struct hci_uart *hu;
> bool is_suspended; /* suspend/resume flag */
> int irq;
> @@ -70,10 +73,11 @@ struct bcm_data {
> struct sk_buff_head txq;
>
> struct bcm_device *dev;
> + struct work_struct pm_work;
> };
>
> /* List of BCM BT UART devices */
> -static DEFINE_SPINLOCK(bcm_device_lock);
> +static DEFINE_MUTEX(bcm_device_lock);
> static LIST_HEAD(bcm_device_list);
>
> static int bcm_set_baudrate(struct hci_uart *hu, unsigned int speed)
> @@ -163,7 +167,7 @@ static const struct bcm_set_sleep_mode default_sleep_params = {
> .bt_wake_active = 1, /* BT_WAKE active mode: 1 = high, 0 = low */
> .host_wake_active = 0, /* HOST_WAKE active mode: 1 = high, 0 = low */
> .allow_host_sleep = 1, /* Allow host sleep in SCO flag */
> - .combine_modes = 0, /* Combine sleep and LPM flag */
> + .combine_modes = 1, /* Combine sleep and LPM flag */
> .tristate_control = 0, /* Allow tri-state control of UART tx flag */
> /* Irrelevant USB flags */
> .usb_auto_sleep = 0,
> @@ -196,6 +200,19 @@ static int bcm_setup_sleep(struct hci_uart *hu)
> return 0;
> }
>
> +static void bcm_pm_runtime_work(struct work_struct *work)
> +{
> + struct bcm_data *bcm = container_of(work, struct bcm_data, pm_work);
> +
> + mutex_lock(&bcm_device_lock);
> + if (bcm_device_exists(bcm->dev)) {
> + pm_runtime_get_sync(&bcm->dev->pdev->dev);
> + pm_runtime_mark_last_busy(&bcm->dev->pdev->dev);
> + pm_runtime_put_autosuspend(&bcm->dev->pdev->dev);
> + }
> + mutex_unlock(&bcm_device_lock);
> +}
> +
> static int bcm_open(struct hci_uart *hu)
> {
> struct bcm_data *bcm;
> @@ -211,7 +228,7 @@ static int bcm_open(struct hci_uart *hu)
>
> hu->priv = bcm;
>
> - spin_lock(&bcm_device_lock);
> + mutex_lock(&bcm_device_lock);
> list_for_each(p, &bcm_device_list) {
> struct bcm_device *dev = list_entry(p, struct bcm_device, list);
>
> @@ -222,17 +239,19 @@ static int bcm_open(struct hci_uart *hu)
> if (hu->tty->dev->parent == dev->pdev->dev.parent) {
> bcm->dev = dev;
> hu->init_speed = dev->init_speed;
> -#ifdef CONFIG_PM_SLEEP
> +#ifdef CONFIG_PM
> dev->hu = hu;
> #endif
> break;
> }
> }
>
> - if (bcm->dev)
> + if (bcm->dev) {
> bcm_gpio_set_power(bcm->dev, true);
> + INIT_WORK(&bcm->pm_work, bcm_pm_runtime_work);
> + }
>
> - spin_unlock(&bcm_device_lock);
> + mutex_unlock(&bcm_device_lock);
>
> return 0;
> }
> @@ -245,18 +264,23 @@ static int bcm_close(struct hci_uart *hu)
> BT_DBG("hu %p", hu);
>
> /* Protect bcm->dev against removal of the device or driver */
> - spin_lock(&bcm_device_lock);
> + mutex_lock(&bcm_device_lock);
> if (bcm_device_exists(bdev)) {
> bcm_gpio_set_power(bdev, false);
> -#ifdef CONFIG_PM_SLEEP
> +#ifdef CONFIG_PM
> bdev->hu = NULL;
> if (device_can_wakeup(&bdev->pdev->dev)) {
> devm_free_irq(&bdev->pdev->dev, bdev->irq, bdev);
> device_init_wakeup(&bdev->pdev->dev, false);
> }
> +
> + pm_runtime_disable(&bdev->pdev->dev);
> + pm_runtime_set_suspended(&bdev->pdev->dev);
> #endif
> }
> - spin_unlock(&bcm_device_lock);
> + mutex_unlock(&bcm_device_lock);
> +
> + cancel_work_sync(&bcm->pm_work);
>
> skb_queue_purge(&bcm->txq);
> kfree_skb(bcm->rx_skb);
> @@ -283,12 +307,16 @@ static irqreturn_t bcm_host_wake(int irq, void *data)
>
> BT_DBG("Host wake IRQ for %s", dev->name);
>
> + pm_runtime_get(&dev->pdev->dev);
> + pm_runtime_mark_last_busy(&dev->pdev->dev);
> + pm_runtime_put_autosuspend(&dev->pdev->dev);
> +
> return IRQ_HANDLED;
> }
>
> static int bcm_setup(struct hci_uart *hu)
> {
> -#ifdef CONFIG_PM_SLEEP
> +#ifdef CONFIG_PM
> struct bcm_data *bcm = hu->priv;
> struct bcm_device *bdev = bcm->dev;
> #endif
> @@ -351,7 +379,7 @@ finalize:
> return err;
>
> /* If it is not a platform device, do not enable PM functionalities */
> - spin_lock(&bcm_device_lock);
> + mutex_lock(&bcm_device_lock);
> if (!bcm_device_exists(bdev))
> goto unlock;
>
> @@ -363,10 +391,16 @@ finalize:
> goto unlock;
>
> device_init_wakeup(&bdev->pdev->dev, true);
> +
> + pm_runtime_set_autosuspend_delay(&bdev->pdev->dev,
> + BCM_AUTOSUSPEND_DELAY);
> + pm_runtime_use_autosuspend(&bdev->pdev->dev);
> + pm_runtime_set_active(&bdev->pdev->dev);
> + pm_runtime_enable(&bdev->pdev->dev);
> }
>
> unlock:
> - spin_unlock(&bcm_device_lock);
> + mutex_unlock(&bcm_device_lock);
>
> err = bcm_setup_sleep(hu);
> #endif
> @@ -383,6 +417,7 @@ static const struct h4_recv_pkt bcm_recv_pkts[] = {
> static int bcm_recv(struct hci_uart *hu, const void *data, int count)
> {
> struct bcm_data *bcm = hu->priv;
> + int ret;
>
> if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
> return -EUNATCH;
> @@ -390,13 +425,20 @@ static int bcm_recv(struct hci_uart *hu, const void *data, int count)
> bcm->rx_skb = h4_recv_buf(hu->hdev, bcm->rx_skb, data, count,
> bcm_recv_pkts, ARRAY_SIZE(bcm_recv_pkts));
> if (IS_ERR(bcm->rx_skb)) {
> - int err = PTR_ERR(bcm->rx_skb);
> - BT_ERR("%s: Frame reassembly failed (%d)", hu->hdev->name, err);
> + ret = PTR_ERR(bcm->rx_skb);
> + BT_ERR("%s: Frame reassembly failed (%d)", hu->hdev->name, ret);
> bcm->rx_skb = NULL;
> - return err;
> - }
> + } else
> + ret = count;
>
> - return count;
> + /* mutex_lock/unlock can not be used here as this function is called
> + * from hci_uart_tty_receive under spinlock.
> + * Defer pm_runtime_* calls to work queue
> + */
> + if (bcm->dev)
> + schedule_work(&bcm->pm_work);
> +
> + return ret;
> }
>
> static int bcm_enqueue(struct hci_uart *hu, struct sk_buff *skb)
> @@ -415,10 +457,89 @@ static int bcm_enqueue(struct hci_uart *hu, struct sk_buff *skb)
> static struct sk_buff *bcm_dequeue(struct hci_uart *hu)
> {
> struct bcm_data *bcm = hu->priv;
> + struct sk_buff *skb = NULL;
> + struct bcm_device *bdev = NULL;
> +
> + mutex_lock(&bcm_device_lock);
> +
> + if (bcm_device_exists(bcm->dev)) {
> + bdev = bcm->dev;
> + pm_runtime_get_sync(&bdev->pdev->dev);
> + }
> +
> + skb = skb_dequeue(&bcm->txq);
> +
> + if (bdev) {
> + pm_runtime_mark_last_busy(&bdev->pdev->dev);
> + pm_runtime_put_autosuspend(&bdev->pdev->dev);
> + }
> +
> + mutex_unlock(&bcm_device_lock);
> +
> + return skb;
> +}
> +
> +#ifdef CONFIG_PM
> +static void __bcm_suspend(struct bcm_device *dev)
> +{
> + if (!dev->is_suspended) {
> + hci_uart_set_flow_control(dev->hu, true);
> +
> + /* Once this returns, driver suspends BT via GPIO */
> + dev->is_suspended = true;
> + }
> +
> + /* Suspend the device */
> + if (dev->device_wakeup) {
> + gpiod_set_value(dev->device_wakeup, false);
> + BT_DBG("suspend, delaying 15 ms");
> + mdelay(15);
> + }
> +}
> +
> +static void __bcm_resume(struct bcm_device *dev)
> +{
> + if (dev->device_wakeup) {
> + gpiod_set_value(dev->device_wakeup, true);
> + BT_DBG("resume, delaying 15 ms");
> + mdelay(15);
> + }
> +
> + /* When this executes, the device has woken up already */
> + if (dev->is_suspended) {
> + dev->is_suspended = false;
> +
> + hci_uart_set_flow_control(dev->hu, false);
> + }
> +}
> +
> +static int bcm_runtime_suspend(struct device *dev)
> +{
> + struct bcm_device *bdev = platform_get_drvdata(to_platform_device(dev));
> +
> + BT_DBG("");
>
> - return skb_dequeue(&bcm->txq);
> + mutex_lock(&bcm_device_lock);
> + __bcm_suspend(bdev);
> + mutex_unlock(&bcm_device_lock);
> +
> + return 0;
> }
>
> +static int bcm_runtime_resume(struct device *dev)
> +{
> + struct bcm_device *bdev = platform_get_drvdata(to_platform_device(dev));
> +
> + BT_DBG("");
> +
> + mutex_lock(&bcm_device_lock);
> + __bcm_resume(bdev);
> + mutex_unlock(&bcm_device_lock);
> +
> + return 0;
> +}
> +#endif
> +
> #ifdef CONFIG_PM_SLEEP
> /* Platform suspend callback */
> static int bcm_suspend(struct device *dev)
> @@ -428,24 +549,13 @@ static int bcm_suspend(struct device *dev)
>
> BT_DBG("suspend (%p): is_suspended %d", bdev, bdev->is_suspended);
>
> - spin_lock(&bcm_device_lock);
> + mutex_lock(&bcm_device_lock);
>
> if (!bdev->hu)
> goto unlock;
>
> - if (!bdev->is_suspended) {
> - hci_uart_set_flow_control(bdev->hu, true);
> -
> - /* Once this callback returns, driver suspends BT via GPIO */
> - bdev->is_suspended = true;
> - }
> -
> - /* Suspend the device */
> - if (bdev->device_wakeup) {
> - gpiod_set_value(bdev->device_wakeup, false);
> - BT_DBG("suspend, delaying 15 ms");
> - mdelay(15);
> - }
> + if (pm_runtime_active(dev))
> + __bcm_suspend(bdev);
>
> if (device_may_wakeup(&bdev->pdev->dev)) {
> error = enable_irq_wake(bdev->irq);
> @@ -454,7 +564,7 @@ static int bcm_suspend(struct device *dev)
> }
>
> unlock:
> - spin_unlock(&bcm_device_lock);
> + mutex_unlock(&bcm_device_lock);
>
> return 0;
> }
> @@ -466,7 +576,7 @@ static int bcm_resume(struct device *dev)
>
> BT_DBG("resume (%p): is_suspended %d", bdev, bdev->is_suspended);
>
> - spin_lock(&bcm_device_lock);
> + mutex_lock(&bcm_device_lock);
>
> if (!bdev->hu)
> goto unlock;
> @@ -476,21 +586,14 @@ static int bcm_resume(struct device *dev)
> BT_DBG("BCM irq: disabled");
> }
>
> - if (bdev->device_wakeup) {
> - gpiod_set_value(bdev->device_wakeup, true);
> - BT_DBG("resume, delaying 15 ms");
> - mdelay(15);
> - }
> -
> - /* When this callback executes, the device has woken up already */
> - if (bdev->is_suspended) {
> - bdev->is_suspended = false;
> + __bcm_resume(bdev);
>
> - hci_uart_set_flow_control(bdev->hu, false);
> - }
> + pm_runtime_disable(dev);
> + pm_runtime_set_active(dev);
> + pm_runtime_enable(dev);
>
> unlock:
> - spin_unlock(&bcm_device_lock);
> + mutex_unlock(&bcm_device_lock);
>
> return 0;
> }
> @@ -635,9 +738,9 @@ static int bcm_probe(struct platform_device *pdev)
> dev_info(&pdev->dev, "%s device registered.\n", dev->name);
>
> /* Place this instance on the device list */
> - spin_lock(&bcm_device_lock);
> + mutex_lock(&bcm_device_lock);
> list_add_tail(&dev->list, &bcm_device_list);
> - spin_unlock(&bcm_device_lock);
> + mutex_unlock(&bcm_device_lock);
>
> bcm_gpio_set_power(dev, false);
>
> @@ -648,9 +751,9 @@ static int bcm_remove(struct platform_device *pdev)
> {
> struct bcm_device *dev = platform_get_drvdata(pdev);
>
> - spin_lock(&bcm_device_lock);
> + mutex_lock(&bcm_device_lock);
> list_del(&dev->list);
> - spin_unlock(&bcm_device_lock);
> + mutex_unlock(&bcm_device_lock);
>
> acpi_dev_remove_driver_gpios(ACPI_COMPANION(&pdev->dev));
>
> @@ -684,7 +787,10 @@ MODULE_DEVICE_TABLE(acpi, bcm_acpi_match);
> #endif
>
> /* Platform suspend and resume callbacks */
> -static SIMPLE_DEV_PM_OPS(bcm_pm_ops, bcm_suspend, bcm_resume);
> +static const struct dev_pm_ops bcm_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(bcm_suspend, bcm_resume)
> + SET_RUNTIME_PM_OPS(bcm_runtime_suspend, bcm_runtime_resume, NULL)
> +};
I don't think is going to fly whey CONFIG_PM=n.
This is way to many #ifdef for my taste. I think the power management subsystem needs to get their stuff together and provide better integration. This simple driver becomes a #ifdef nightmare.
Regards
Marcel
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