SEMITEK / GK6X keyboards - working around buggy descriptor
Dear linux-input,
The "GK6X" series is a series of USB keyboards that feature swappable key switches, programmable mappings, and LED effects. There are many variants, sold by multiple manufacturers (see below). I believe all of these keyboards use the same vendor ID (0x1EA7) and product ID (0x0907), and the same or closely related firmware.
The keyboard supports full N-key rollover, but in Linux, only the first six keypresses are recognized. This appears to be caused by an erroneous report descriptor, which labels the input field as "array" when it should be "variable".
The report descriptor for interface 2 is:
$ od -Ax -tx1 /sys/bus/hid/devices/0003:1EA7:0907.0005/report_descriptor 000000 05 01 09 80 a1 01 85 01 19 81 29 83 15 00 25 01 000010 95 03 75 01 81 02 95 01 75 05 81 01 c0 05 0c 09 000020 01 a1 01 85 02 15 00 25 01 95 12 75 01 0a 83 01 000030 0a 8a 01 0a 92 01 0a 94 01 09 cd 09 b7 09 b6 09 000040 b5 09 e2 09 ea 09 e9 0a 21 02 0a 23 02 0a 24 02 000050 0a 25 02 0a 26 02 0a 27 02 0a 2a 02 81 02 95 01 000060 75 0e 81 01 c0 05 01 09 06 a1 01 85 04 05 07 95 000070 01 75 08 81 03 95 e8 75 01 15 00 25 01 05 07 19 000080 00 29 e7 81 00 c0 05 01 09 02 a1 01 85 05 09 01 000090 a1 00 05 09 19 01 29 08 15 00 25 01 95 08 75 01 0000a0 81 02 05 01 09 30 09 31 16 01 f8 26 ff 07 95 02 0000b0 75 0c 81 06 09 38 15 81 25 7f 95 01 75 08 81 06 0000c0 05 0c 0a 38 02 95 01 81 06 c0 c0 0000cb
At offset 0x83, "81 00" should apparently be "81 02" instead.
It looks to me like it should be possible to work around this in Linux by patching the descriptor, as is done for several other HID devices. Would that be the best way to fix this? What would need to be done to add such a driver?
List of known variants (from https://github.com/pixeltris/GK6X/blob/master/Build/Data/device/modellist.json):
Dierya DK61
Dierya DK66
GK21S-RGB
GK61 RGB
GK61-RGB-V2
GK61S RGB
GK61S RGB LED
GK61X RGB
GK61XS RGB
GK64 RGB
GK64 RGB V1
GK64S
GK64S RGB V2
GK64X-RGB
GK64XS-RGB
GK68 RGB
GK68X RGB
GK68XS RGB
GK73 RGB
GK73S RGB
GK84S RGB
GK87 RGB
GK87S RGB
GK96L-X RGB
GK96L-XS RGB
GK96X-RGB
GK96XS-RGB
GK98 RGB
GK99-RGB
GS66 RGB LED
GS66S RGB LED
GX66 RGB
GX66S RGB
Knight 22Key RGB
Knight 86Key RGB
Nature 86Key RGB
RANGER 87Key RGB
RANGER 89Key RGB
RANGERS 87Key RGB
RANGERS 89Key RGB
SK103 RGB
SK103S RGB
SK104 2RGB
SK104 RGB
SK61 RGB
SK61-RGB
SK61S RGB
SK61S-RGB
SK61X RGB
SK61XS RGB
SK64 RGB
SK64-RGB
SK64S RGB
SK64S-RGB
SK64X RGB
SK64XS RGB
SK64XS-2RGB
SK66-2RGB
SK66-RGB
SK66S-2RGB
SK66S-RGB
SK68 RGB
SK68S RGB
SK70 RGB
SK70S RGB
SK71 RGB
SK71S RGB
SK73 RGB
SK73S RGB
SK84S-RGB
SK87 RGB
SK87-RGB
SK87S RGB
SK87S-2RGB
SK96 RGB
SK96S RGB
TK09R-104 RGB-KR
TK09R-104 RGB-RU
TK09R-104 RGB-UK
TK09R-104 RGB-US
TK09R-104 RGBS-US
TK09R-105 RGB-DE
TK09R-105 RGB-EN
TK09R-105 RGB-ES
TK09R-105 RGB-FR
TK09R-105 RGB-IT
TK09R-G18-3330
TK09R-LC-V3
TK09R-MousePad
Woo-dy 67Key RGB
Full descriptor dump (lsusb -v):
Bus 002 Device 006: ID 1ea7:0907 SHARKOON Technologies GmbH Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 0
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x1ea7 SHARKOON Technologies GmbH
idProduct 0x0907
bcdDevice 3.00
iManufacturer 1 SEMITEK
iProduct 2 USB-HID Gaming Keyboard
iSerial 3 SN0000000001
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x005b
bNumInterfaces 3
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xa0
(Bus Powered)
Remote Wakeup
MaxPower 100mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 3 Human Interface Device
bInterfaceSubClass 1 Boot Interface Subclass
bInterfaceProtocol 1 Keyboard
iInterface 0
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.11
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 64
Report Descriptor: (length is 64)
Item(Global): Usage Page, data= [ 0x01 ] 1
Generic Desktop Controls
Item(Local ): Usage, data= [ 0x06 ] 6
Keyboard
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Global): Usage Page, data= [ 0x07 ] 7
Keyboard
Item(Local ): Usage Minimum, data= [ 0xe0 ] 224
Control Left
Item(Local ): Usage Maximum, data= [ 0xe7 ] 231
GUI Right
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0x01 ] 1
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Global): Report Count, data= [ 0x08 ] 8
Item(Main ): Input, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x01 ] 1
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Main ): Input, data= [ 0x03 ] 3
Constant Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x03 ] 3
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Global): Usage Page, data= [ 0x08 ] 8
LEDs
Item(Local ): Usage Minimum, data= [ 0x01 ] 1
NumLock
Item(Local ): Usage Maximum, data= [ 0x03 ] 3
Scroll Lock
Item(Main ): Output, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x01 ] 1
Item(Global): Report Size, data= [ 0x05 ] 5
Item(Main ): Output, data= [ 0x03 ] 3
Constant Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x06 ] 6
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0xa4 0x00 ] 164
Item(Global): Usage Page, data= [ 0x07 ] 7
Keyboard
Item(Local ): Usage Minimum, data= [ 0x00 ] 0
No Event
Item(Local ): Usage Maximum, data= [ 0xa4 ] 164
ExSel
Item(Main ): Input, data= [ 0x00 ] 0
Data Array Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0008 1x 8 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 3 Human Interface Device
bInterfaceSubClass 0
bInterfaceProtocol 0
iInterface 0
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.11
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 34
Report Descriptor: (length is 34)
Item(Global): Usage Page, data= [ 0x00 0xff ] 65280
(null)
Item(Local ): Usage, data= [ 0x50 ] 80
(null)
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Local ): Usage, data= [ 0x02 ] 2
(null)
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0xff 0x00 ] 255
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Global): Report Count, data= [ 0x40 ] 64
Item(Main ): Input, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Local ): Usage, data= [ 0x03 ] 3
(null)
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0xff 0x00 ] 255
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Global): Report Count, data= [ 0x40 ] 64
Item(Main ): Output, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x04 EP 4 OUT
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 3 Human Interface Device
bInterfaceSubClass 0
bInterfaceProtocol 0
iInterface 0
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.11
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 203
Report Descriptor: (length is 203)
Item(Global): Usage Page, data= [ 0x01 ] 1
Generic Desktop Controls
Item(Local ): Usage, data= [ 0x80 ] 128
System Control
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Global): Report ID, data= [ 0x01 ] 1
Item(Local ): Usage Minimum, data= [ 0x81 ] 129
System Power Down
Item(Local ): Usage Maximum, data= [ 0x83 ] 131
System Wake Up
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0x01 ] 1
Item(Global): Report Count, data= [ 0x03 ] 3
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Main ): Input, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x01 ] 1
Item(Global): Report Size, data= [ 0x05 ] 5
Item(Main ): Input, data= [ 0x01 ] 1
Constant Array Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Item(Global): Usage Page, data= [ 0x0c ] 12
Consumer
Item(Local ): Usage, data= [ 0x01 ] 1
Consumer Control
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Global): Report ID, data= [ 0x02 ] 2
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0x01 ] 1
Item(Global): Report Count, data= [ 0x12 ] 18
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Local ): Usage, data= [ 0x83 0x01 ] 387
AL Consumer Control Configuration
Item(Local ): Usage, data= [ 0x8a 0x01 ] 394
AL Email Reader
Item(Local ): Usage, data= [ 0x92 0x01 ] 402
AL Calculator
Item(Local ): Usage, data= [ 0x94 0x01 ] 404
AL Local Machine Browser
Item(Local ): Usage, data= [ 0xcd ] 205
Play/Pause
Item(Local ): Usage, data= [ 0xb7 ] 183
Stop
Item(Local ): Usage, data= [ 0xb6 ] 182
Scan Previous Track
Item(Local ): Usage, data= [ 0xb5 ] 181
Scan Next Track
Item(Local ): Usage, data= [ 0xe2 ] 226
Mute
Item(Local ): Usage, data= [ 0xea ] 234
Volume Decrement
Item(Local ): Usage, data= [ 0xe9 ] 233
Volume Increment
Item(Local ): Usage, data= [ 0x21 0x02 ] 545
AC Search
Item(Local ): Usage, data= [ 0x23 0x02 ] 547
AC Home
Item(Local ): Usage, data= [ 0x24 0x02 ] 548
AC Back
Item(Local ): Usage, data= [ 0x25 0x02 ] 549
AC Forward
Item(Local ): Usage, data= [ 0x26 0x02 ] 550
AC Stop
Item(Local ): Usage, data= [ 0x27 0x02 ] 551
AC Refresh
Item(Local ): Usage, data= [ 0x2a 0x02 ] 554
(null)
Item(Main ): Input, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x01 ] 1
Item(Global): Report Size, data= [ 0x0e ] 14
Item(Main ): Input, data= [ 0x01 ] 1
Constant Array Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Item(Global): Usage Page, data= [ 0x01 ] 1
Generic Desktop Controls
Item(Local ): Usage, data= [ 0x06 ] 6
Keyboard
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Global): Report ID, data= [ 0x04 ] 4
Item(Global): Usage Page, data= [ 0x07 ] 7
Keyboard
Item(Global): Report Count, data= [ 0x01 ] 1
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Main ): Input, data= [ 0x03 ] 3
Constant Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0xe8 ] 232
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0x01 ] 1
Item(Global): Usage Page, data= [ 0x07 ] 7
Keyboard
Item(Local ): Usage Minimum, data= [ 0x00 ] 0
No Event
Item(Local ): Usage Maximum, data= [ 0xe7 ] 231
GUI Right
Item(Main ): Input, data= [ 0x00 ] 0
Data Array Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Item(Global): Usage Page, data= [ 0x01 ] 1
Generic Desktop Controls
Item(Local ): Usage, data= [ 0x02 ] 2
Mouse
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Global): Report ID, data= [ 0x05 ] 5
Item(Local ): Usage, data= [ 0x01 ] 1
Pointer
Item(Main ): Collection, data= [ 0x00 ] 0
Physical
Item(Global): Usage Page, data= [ 0x09 ] 9
Buttons
Item(Local ): Usage Minimum, data= [ 0x01 ] 1
Button 1 (Primary)
Item(Local ): Usage Maximum, data= [ 0x08 ] 8
(null)
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0x01 ] 1
Item(Global): Report Count, data= [ 0x08 ] 8
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Main ): Input, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Usage Page, data= [ 0x01 ] 1
Generic Desktop Controls
Item(Local ): Usage, data= [ 0x30 ] 48
Direction-X
Item(Local ): Usage, data= [ 0x31 ] 49
Direction-Y
Item(Global): Logical Minimum, data= [ 0x01 0xf8 ] 63489
Item(Global): Logical Maximum, data= [ 0xff 0x07 ] 2047
Item(Global): Report Count, data= [ 0x02 ] 2
Item(Global): Report Size, data= [ 0x0c ] 12
Item(Main ): Input, data= [ 0x06 ] 6
Data Variable Relative No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Local ): Usage, data= [ 0x38 ] 56
Wheel
Item(Global): Logical Minimum, data= [ 0x81 ] 129
Item(Global): Logical Maximum, data= [ 0x7f ] 127
Item(Global): Report Count, data= [ 0x01 ] 1
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Main ): Input, data= [ 0x06 ] 6
Data Variable Relative No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Usage Page, data= [ 0x0c ] 12
Consumer
Item(Local ): Usage, data= [ 0x38 0x02 ] 568
AC Pan
Item(Global): Report Count, data= [ 0x01 ] 1
Item(Main ): Input, data= [ 0x06 ] 6
Data Variable Relative No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Item(Main ): End Collection, data=none
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 1Device Status: 0x0000
(Bus Powered)