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> > --- > V3 -> V4: > - Reorder quirk entries to be in numerical order according to the vendor > ID and product ID. > - Add patch version information. > V2 -> V3: > - Change subject (Bluetooth: btusb: CSR chip hangs when unbound -> > USB: core: skip unconfiguration if device doesn't support it). > - Improve quirk checking. > - Allow to test quirk interactively. > V1 -> V2: > - Use quirk feature for the exception. > > 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..7c86c8d61570 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 */ > } > } > @@ -394,6 +397,9 @@ static const struct usb_device_id usb_quirk_list[] = { > /* ELMO L-12F document camera */ > { USB_DEVICE(0x09a1, 0x0028), .driver_info = USB_QUIRK_DELAY_CTRL_MSG }, > > + /* CSR Bluetooth */ > + { USB_DEVICE(0x0a12, 0x0001), .driver_info = USB_QUIRK_SKIP_UNCONFIGURE }, > + NAK. I said this before. The VID:PID 0a12:0001 is used in millions of products that work correctly. Only because some counterfeit products get things wrong doesn’t mean all get marked as broken. Regards Marcel