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 1 Device Status: 0x0000 (Bus Powered)
