Re: [PATCH v5 1/4] Bluetooth: hci_bcm: Disallow set_baudrate for BCM4354

From: Marcel Holtmann
Date: Fri Nov 15 2019 - 02:59:32 EST


Hi Abhishek,

> Without updating the patchram, the BCM4354 does not support a higher
> operating speed. The normal bcm_setup follows the correct order
> (init_speed, patchram and then oper_speed) but the serdev driver will
> set the operating speed before calling the hu->setup function. Thus,
> for the BCM4354, don't set the operating speed before patchram.
>
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx>
> ---
>
> Changes in v5: None
> Changes in v4: None
> Changes in v3: None
> Changes in v2: None
>
> drivers/bluetooth/hci_bcm.c | 31 +++++++++++++++++++++++++++++--
> 1 file changed, 29 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
> index 0f851c0dde7f..ee40003008d8 100644
> --- a/drivers/bluetooth/hci_bcm.c
> +++ b/drivers/bluetooth/hci_bcm.c
> @@ -47,6 +47,14 @@
>
> #define BCM_NUM_SUPPLIES 2
>
> +/**
> + * struct bcm_device_data - device specific data
> + * @no_early_set_baudrate: Disallow set baudrate before driver setup()
> + */
> +struct bcm_device_data {
> + bool no_early_set_baudrate;
> +};
> +
> /**
> * struct bcm_device - device driver resources
> * @serdev_hu: HCI UART controller struct
> @@ -79,6 +87,7 @@
> * @hu: pointer to HCI UART controller struct,
> * used to disable flow control during runtime suspend and system sleep
> * @is_suspended: whether flow control is currently disabled
> + * @no_early_set_baudrate: don't set_baudrate before setup()
> */
> struct bcm_device {
> /* Must be the first member, hci_serdev.c expects this. */
> @@ -112,6 +121,7 @@ struct bcm_device {
> struct hci_uart *hu;
> bool is_suspended;
> #endif
> + bool no_early_set_baudrate;
> };
>
> /* generic bcm uart resources */
> @@ -447,7 +457,13 @@ static int bcm_open(struct hci_uart *hu)
> if (bcm->dev) {
> hci_uart_set_flow_control(hu, true);
> hu->init_speed = bcm->dev->init_speed;
> - hu->oper_speed = bcm->dev->oper_speed;
> +
> + /* If oper_speed is set, ldisc/serdev will set the baudrate
> + * before calling setup()
> + */
> + if (!bcm->dev->no_early_set_baudrate)
> + hu->oper_speed = bcm->dev->oper_speed;
> +
> err = bcm_gpio_set_power(bcm->dev, true);
> hci_uart_set_flow_control(hu, false);
> if (err)
> @@ -565,6 +581,8 @@ static int bcm_setup(struct hci_uart *hu)
> /* Operational speed if any */
> if (hu->oper_speed)
> speed = hu->oper_speed;
> + else if (bcm->dev && bcm->dev->oper_speed)
> + speed = bcm->dev->oper_speed;
> else if (hu->proto->oper_speed)
> speed = hu->proto->oper_speed;
> else
> @@ -1374,6 +1392,7 @@ static struct platform_driver bcm_driver = {
> static int bcm_serdev_probe(struct serdev_device *serdev)
> {
> struct bcm_device *bcmdev;
> + const struct bcm_device_data *data;
> int err;
>
> bcmdev = devm_kzalloc(&serdev->dev, sizeof(*bcmdev), GFP_KERNEL);
> @@ -1408,6 +1427,10 @@ static int bcm_serdev_probe(struct serdev_device *serdev)
> if (err)
> dev_err(&serdev->dev, "Failed to power down\n");
>
> + data = device_get_match_data(bcmdev->dev);
> + if (data)
> + bcmdev->no_early_set_baudrate = data->no_early_set_baudrate;
> +
> return hci_uart_register_device(&bcmdev->serdev_hu, &bcm_proto);
> }
>
> @@ -1419,12 +1442,16 @@ static void bcm_serdev_remove(struct serdev_device *serdev)
> }
>
> #ifdef CONFIG_OF
> +struct bcm_device_data bcm4354_device_data = {
> + .no_early_set_baudrate = true,
> +};
> +
> static const struct of_device_id bcm_bluetooth_of_match[] = {
> { .compatible = "brcm,bcm20702a1" },
> { .compatible = "brcm,bcm4345c5" },
> { .compatible = "brcm,bcm4330-bt" },
> { .compatible = "brcm,bcm43438-bt" },
> - { .compatible = "brcm,bcm43540-bt" },
> + { .compatible = "brcm,bcm43540-bt", .data = &bcm4354_device_data },

this looks good to me. Can some users of the other devices test this patch so we ensure that it wonât break other devices.

Regards

Marcel