Re: [PATCH] USB: Add quirk for WORLDE easykey.25 MIDI keyboard

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Fri, Jan 20, 2017 at 07:46:34PM +0100, Lukáš Lalinský wrote:
> Add a quirk for WORLDE easykey.25 MIDI keyboard (idVendor=0218,
> idProduct=0401). The device reports that it has config string
> descriptor at index 3, but when the system selects the configuration
> and tries to get the description, it returns a -EPROTO error,
> the communication restarts and this keeps repeating over and over again.
> Not requesting the string descriptor makes the device work correctly.

Always use scripts/get_maintainer.pl to determine who to send patches
to, and what mailing list.  You forgot linux-usb@vger, which I've now
added...

> 
> Relevant info from Wireshark:
> 
> [...]
> 
> CONFIGURATION DESCRIPTOR
>     bLength: 9
>     bDescriptorType: 0x02 (CONFIGURATION)
>     wTotalLength: 101
>     bNumInterfaces: 2
>     bConfigurationValue: 1
>     iConfiguration: 3
>     Configuration bmAttributes: 0xc0  SELF-POWERED  NO REMOTE-WAKEUP
>         1... .... = Must be 1: Must be 1 for USB 1.1 and higher
>         .1.. .... = Self-Powered: This device is SELF-POWERED
>         ..0. .... = Remote Wakeup: This device does NOT support remote wakeup
>     bMaxPower: 50  (100mA)
> 
> [...]
> 
>      45 0.369104       host                  2.38.0                USB      64     GET DESCRIPTOR Request STRING
> 
> [...]
> 
> URB setup
>     bmRequestType: 0x80
>         1... .... = Direction: Device-to-host
>         .00. .... = Type: Standard (0x00)
>         ...0 0000 = Recipient: Device (0x00)
>     bRequest: GET DESCRIPTOR (6)
>     Descriptor Index: 0x03
>     bDescriptorType: 0x03
>     Language Id: English (United States) (0x0409)
>     wLength: 255
> 
>      46 0.369255       2.38.0                host                  USB      64     GET DESCRIPTOR Response STRING[Malformed Packet]
> 
> [...]
> 
> Frame 46: 64 bytes on wire (512 bits), 64 bytes captured (512 bits) on interface 0
> USB URB
>     [Source: 2.38.0]
>     [Destination: host]
>     URB id: 0xffff88021f62d480
>     URB type: URB_COMPLETE ('C')
>     URB transfer type: URB_CONTROL (0x02)
>     Endpoint: 0x80, Direction: IN
>     Device: 38
>     URB bus id: 2
>     Device setup request: not relevant ('-')
>     Data: present (0)
>     URB sec: 1484896277
>     URB usec: 455031
>     URB status: Protocol error (-EPROTO) (-71)
>     URB length [bytes]: 0
>     Data length [bytes]: 0
>     [Request in: 45]
>     [Time from request: 0.000151000 seconds]
>     Unused Setup Header
>     Interval: 0
>     Start frame: 0
>     Copy of Transfer Flags: 0x00000200
>     Number of ISO descriptors: 0
> [Malformed Packet: USB]
>     [Expert Info (Error/Malformed): Malformed Packet (Exception occurred)]
>         [Malformed Packet (Exception occurred)]
>         [Severity level: Error]
>         [Group: Malformed]
> 
> Signed-off-by: Lukáš Lalinský <lukas@oxygene.sk>
> ---
>  drivers/usb/core/quirks.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
> index d2e50a2..24f9f98 100644
> --- a/drivers/usb/core/quirks.c
> +++ b/drivers/usb/core/quirks.c
> @@ -37,6 +37,10 @@ static const struct usb_device_id usb_quirk_list[] = {
>  	/* CBM - Flash disk */
>  	{ USB_DEVICE(0x0204, 0x6025), .driver_info = USB_QUIRK_RESET_RESUME },
>  
> +	/* WORLDE easy key (easykey.25) MIDI controller  */
> +	{ USB_DEVICE(0x0218, 0x0401), .driver_info =
> +			USB_QUIRK_CONFIG_INTF_STRINGS },

That's odd, how does other operating systems handle this device?

thanks,

greg k-h