usb: gadget: f_hid: added GET_IDLE and SET_IDLE handlers

The USB HID standard declares mandatory support for GET_IDLE and SET_IDLE
requests for Boot Keyboard. Most hosts can handle their absence, but others
like some old/strange UEFIs and BIOSes consider this a critical error
and refuse to work with f_hid.

This primitive implementation of saving and returning idle is sufficient
to meet the requirements of the standard and these devices.

Acked-by: Felipe Balbi <balbi@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Maxim Devaev <mdevaev@gmail.com>
Link: https://lore.kernel.org/r/20210721180351.129450-1-mdevaev@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Maxim Devaev 2021-07-21 21:03:51 +03:00 committed by Greg Kroah-Hartman
parent 2867652e47
commit afcff6dc69

View File

@ -41,6 +41,7 @@ struct f_hidg {
unsigned char bInterfaceSubClass;
unsigned char bInterfaceProtocol;
unsigned char protocol;
unsigned char idle;
unsigned short report_desc_length;
char *report_desc;
unsigned short report_length;
@ -537,6 +538,14 @@ static int hidg_setup(struct usb_function *f,
goto respond;
break;
case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
| HID_REQ_GET_IDLE):
VDBG(cdev, "get_idle\n");
length = min_t(unsigned int, length, 1);
((u8 *) req->buf)[0] = hidg->idle;
goto respond;
break;
case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
| HID_REQ_SET_REPORT):
VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
@ -560,6 +569,14 @@ static int hidg_setup(struct usb_function *f,
goto stall;
break;
case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
| HID_REQ_SET_IDLE):
VDBG(cdev, "set_idle\n");
length = 0;
hidg->idle = value;
goto respond;
break;
case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
| USB_REQ_GET_DESCRIPTOR):
switch (value >> 8) {
@ -787,6 +804,7 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
hidg->protocol = HID_REPORT_PROTOCOL;
hidg->idle = 1;
hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
hidg_ss_in_comp_desc.wBytesPerInterval =
cpu_to_le16(hidg->report_length);