[RFC v2 8/9] Bluetooth: drop HCI_UART_INIT_PENDING support
Marcel Holtmann
marcel at holtmann.org
Tue Jan 2 03:04:40 PST 2018
Hi Martin,
> The three-wire (H5) protocol is the only protocol which uses
> HCI_UART_INIT_PENDING.
> Unfortunately the benefits of using this flag are currently unknown. It
> was added in commit 9f2aee848fe6 ("Bluetooth: Add delayed init sequence
> support for UART controllers"). In my experiments (with the
> "rtk_hciattach" tool - a customized version of hciattach for Realtek
> chipsets) I started the tool before and after this patch while the
> Bluetooth chipset was disabled (by pulling it's enable GPIO LOW). In
> both cases hci0 was not created - thus HCI_UART_INIT_PENDING is not
> required in that case.
>
> Removing this code also has another benefit: hci_serdev.c does not
> support the delayed initialization / registration. Thus the protocol
> implementation (hci_h5) never receives any data with this check still
> in place. For the H5 protocol this means that the initialization never
> completes (because the sync response never arrives). Even if the
> initialization would succeed later on the drivers would call
> hci_uart_init_ready() which schedules the registration which is
> currently not implemented by hci_serdev.c.
>
> Removing the HCI_UART_INIT_PENDING check makes the code easier to read
> and also fixes the initalization of devices (implemented with the serdev
> library) which use the H5 protocol.
>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl at googlemail.com>
I really like Johan to ack this one, but generally I am fine with removing unneeded code.
We might also want to look at hciattach to btattach code and make sure it gets removed there as well. I am not even sure anybody used hciattach with H:5 ever.
> ---
> drivers/bluetooth/hci_h5.c | 3 ---
> drivers/bluetooth/hci_ldisc.c | 38 --------------------------------------
> drivers/bluetooth/hci_serdev.c | 3 ---
> drivers/bluetooth/hci_uart.h | 4 +---
> 4 files changed, 1 insertion(+), 47 deletions(-)
>
> diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c
> index 6a8d0d06aba7..6cfc2f276250 100644
> --- a/drivers/bluetooth/hci_h5.c
> +++ b/drivers/bluetooth/hci_h5.c
> @@ -210,8 +210,6 @@ static int h5_open(struct hci_uart *hu)
>
> h5->tx_win = H5_TX_WIN_MAX;
>
> - set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags);
> -
> /* Send initial sync request */
> h5_link_control(hu, sync, sizeof(sync));
> mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
> @@ -316,7 +314,6 @@ static void h5_handle_internal_rx(struct hci_uart *hu)
> h5->tx_win = (data[2] & 0x07);
> BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win);
> h5->state = H5_ACTIVE;
> - hci_uart_init_ready(hu);
> return;
> } else if (memcmp(data, sleep_req, 2) == 0) {
> BT_DBG("Peer went to sleep");
> diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
> index c823914b3a80..5dd3e1bebfe4 100644
> --- a/drivers/bluetooth/hci_ldisc.c
> +++ b/drivers/bluetooth/hci_ldisc.c
> @@ -195,39 +195,6 @@ static void hci_uart_write_work(struct work_struct *work)
> clear_bit(HCI_UART_SENDING, &hu->tx_state);
> }
>
> -static void hci_uart_init_work(struct work_struct *work)
> -{
> - struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
> - int err;
> - struct hci_dev *hdev;
> -
> - if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
> - return;
> -
> - err = hci_register_dev(hu->hdev);
> - if (err < 0) {
> - BT_ERR("Can't register HCI device");
> - hdev = hu->hdev;
> - hu->hdev = NULL;
> - hci_free_dev(hdev);
> - clear_bit(HCI_UART_PROTO_READY, &hu->flags);
> - hu->proto->close(hu);
> - return;
> - }
> -
> - set_bit(HCI_UART_REGISTERED, &hu->flags);
> -}
> -
> -int hci_uart_init_ready(struct hci_uart *hu)
> -{
> - if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
> - return -EALREADY;
> -
> - schedule_work(&hu->init_ready);
> -
> - return 0;
> -}
> -
> /* ------- Interface to HCI layer ------ */
> /* Initialize device */
> static int hci_uart_open(struct hci_dev *hdev)
> @@ -490,7 +457,6 @@ static int hci_uart_tty_open(struct tty_struct *tty)
> hu->alignment = 1;
> hu->padding = 0;
>
> - INIT_WORK(&hu->init_ready, hci_uart_init_work);
> INIT_WORK(&hu->write_work, hci_uart_write_work);
>
> percpu_init_rwsem(&hu->proto_lock);
> @@ -653,9 +619,6 @@ static int hci_uart_register_dev(struct hci_uart *hu)
> else
> hdev->dev_type = HCI_PRIMARY;
>
> - if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
> - return 0;
> -
> if (hci_register_dev(hdev) < 0) {
> BT_ERR("Can't register HCI device");
> hu->hdev = NULL;
> @@ -699,7 +662,6 @@ static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
> unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
> BIT(HCI_UART_RESET_ON_INIT) |
> BIT(HCI_UART_CREATE_AMP) |
> - BIT(HCI_UART_INIT_PENDING) |
> BIT(HCI_UART_EXT_CONFIG) |
> BIT(HCI_UART_VND_DETECT);
>
> diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c
> index e0e6461b9200..fe67eb6d4278 100644
> --- a/drivers/bluetooth/hci_serdev.c
> +++ b/drivers/bluetooth/hci_serdev.c
> @@ -333,9 +333,6 @@ int hci_uart_register_device(struct hci_uart *hu,
> else
> hdev->dev_type = HCI_PRIMARY;
>
> - if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
> - return 0;
> -
> if (hci_register_dev(hdev) < 0) {
> BT_ERR("Can't register HCI device");
> err = -ENODEV;
> diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h
> index 66e8c68e4607..47e755ff4092 100644
> --- a/drivers/bluetooth/hci_uart.h
> +++ b/drivers/bluetooth/hci_uart.h
> @@ -53,7 +53,7 @@
> #define HCI_UART_RAW_DEVICE 0
> #define HCI_UART_RESET_ON_INIT 1
> #define HCI_UART_CREATE_AMP 2
> -#define HCI_UART_INIT_PENDING 3
> +/* 3 is unused - was HCI_UART_INIT_PENDING */
#define HCI_UART_INIT_PENDING 3 /* unused */
I prefer it this way since it is easier on the eyes.
> #define HCI_UART_EXT_CONFIG 4
> #define HCI_UART_VND_DETECT 5
>
> @@ -83,7 +83,6 @@ struct hci_uart {
> unsigned long flags;
> unsigned long hdev_flags;
>
> - struct work_struct init_ready;
> struct work_struct write_work;
>
> const struct hci_uart_proto *proto;
> @@ -115,7 +114,6 @@ int hci_uart_register_device(struct hci_uart *hu, const struct hci_uart_proto *p
> void hci_uart_unregister_device(struct hci_uart *hu);
>
> int hci_uart_tx_wakeup(struct hci_uart *hu);
> -int hci_uart_init_ready(struct hci_uart *hu);
> void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed);
> void hci_uart_set_flow_control(struct hci_uart *hu, bool enable);
> void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
Regards
Marcel
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