Always set a non-zero "Sw. Id." in the lower nibble of the Function/ASE and Software Identifier byte in HID++ 2.0 commands. As per the "Protocol HID++2.0 essential features" section in https://lekensteyn.nl/files/logitech/logitech_hidpp_2.0_specification_draft_2012-06-04.pdf " Software identifier (4 bits, unsigned) A number uniquely defining the software that sends a request. The firmware must copy the software identifier in the response but does not use it in any other ways. 0 Do not use (allows to distinguish a notification from a response). " Link: https://bugzilla.kernel.org/show_bug.cgi?id=215699 Signed-off-by: Bastien Nocera <hadess@xxxxxxxxxx> --- drivers/hid/hid-logitech-hidpp.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c index 86e7a38d8a9a..02f8c99672c7 100644 --- a/drivers/hid/hid-logitech-hidpp.c +++ b/drivers/hid/hid-logitech-hidpp.c @@ -41,6 +41,9 @@ module_param(disable_tap_to_click, bool, 0644); MODULE_PARM_DESC(disable_tap_to_click, "Disable Tap-To-Click mode reporting for touchpads (only on the K400 currently)."); +/* Define a non-zero software ID to identify our own requests */ +#define LINUX_KERNEL_SW_ID 0x06 + #define REPORT_ID_HIDPP_SHORT 0x10 #define REPORT_ID_HIDPP_LONG 0x11 #define REPORT_ID_HIDPP_VERY_LONG 0x12 @@ -343,7 +346,7 @@ static int hidpp_send_fap_command_sync(struct hidpp_device *hidpp, else message->report_id = REPORT_ID_HIDPP_LONG; message->fap.feature_index = feat_index; - message->fap.funcindex_clientid = funcindex_clientid; + message->fap.funcindex_clientid = funcindex_clientid | LINUX_KERNEL_SW_ID; memcpy(&message->fap.params, params, param_count); ret = hidpp_send_message_sync(hidpp, message, response); -- 2.37.2
