Hi Jose,
> Bluetooth Dongles with CSR chip (i.e. USB Bluetooth V4.0 Dongle by
> Trust) hang when they are unbound from 'unbind' sysfs entry and
> can not be bound again.
>
> The reason is CSR chip hangs when usb configuration command with
> index 0 (used to unconfigure) is sent during disconnection.
>
> To avoid this unwanted result, it is necessary not to send this
> command for CSR chip, so a new quirk has been created.
>
> Athough device is not unconfigured, it is better to avoid device
> hanging to be able to operate. Even bluetooth can be previously
> turned off.
> On the other hand, this is not important if usb device is going to
> be bound again (normal behavior), i.e. with usbip.
>
> Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@xxxxxxxxxx>
> ---
> Documentation/admin-guide/kernel-parameters.txt | 2 ++
> drivers/usb/core/message.c | 12 +++++++++---
> drivers/usb/core/quirks.c | 6 ++++++
> include/linux/usb/quirks.h | 3 +++
> 4 files changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 3f1cc5e317ed..71651b888d14 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -6183,6 +6183,8 @@
> pause after every control message);
> o = USB_QUIRK_HUB_SLOW_RESET (Hub needs extra
> delay after resetting its port);
> + p = USB_QUIRK_SKIP_UNCONFIGURE (device doesn't
> + support unconfigure);
> Example: quirks=0781:5580:bk,0a5c:5834:gij
>
> usbhid.mousepoll=
> diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
> index 4d59d927ae3e..9c6cd0c75f4f 100644
> --- a/drivers/usb/core/message.c
> +++ b/drivers/usb/core/message.c
> @@ -2108,9 +2108,15 @@ int usb_set_configuration(struct usb_device *dev, int configuration)
> }
> kfree(new_interfaces);
>
> - ret = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
> - configuration, 0, NULL, 0,
> - USB_CTRL_SET_TIMEOUT, GFP_NOIO);
> + if (configuration == 0 && !cp
> + && (dev->quirks & USB_QUIRK_SKIP_UNCONFIGURE)) {
> + dev_warn(&dev->dev, "device is not unconfigured!\n");
> + ret = 0;
> + } else
> + ret = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
> + configuration, 0, NULL, 0,
> + USB_CTRL_SET_TIMEOUT, GFP_NOIO);
> +
> if (ret && cp) {
> /*
> * All the old state is gone, so what else can we do?
> diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
> index d3c14b5ed4a1..7d42fdc7404c 100644
> --- a/drivers/usb/core/quirks.c
> +++ b/drivers/usb/core/quirks.c
> @@ -138,6 +138,9 @@ static int quirks_param_set(const char *value, const struct kernel_param *kp)
> case 'o':
> flags |= USB_QUIRK_HUB_SLOW_RESET;
> break;
> + case 'p':
> + flags |= USB_QUIRK_SKIP_UNCONFIGURE;
> + break;
> /* Ignore unrecognized flag characters */
> }
> }
> @@ -510,6 +513,9 @@ static const struct usb_device_id usb_quirk_list[] = {
> /* INTEL VALUE SSD */
> { USB_DEVICE(0x8086, 0xf1a5), .driver_info = USB_QUIRK_RESET_RESUME },
>
> + /* CSR Bluetooth */
> + { USB_DEVICE(0x0a12, 0x0001), .driver_info = USB_QUIRK_SKIP_UNCONFIGURE },
> +
NAK. These are billion of devices that are today working correctly. You are not telling these devices they are broken now.
Regards
Marcel
