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* [PATCH v2] usb: gadget: f_hid: added GET_IDLE and SET_IDLE handlers
@ 2021-07-27 18:31 Maxim Devaev
  2021-07-27 18:45 ` Greg KH
  2021-07-27 18:46 ` Greg KH
  0 siblings, 2 replies; 4+ messages in thread
From: Maxim Devaev @ 2021-07-27 18:31 UTC (permalink / raw)
  To: balbi; +Cc: gregkh, sandeen, mdevaev, linux-usb, linux-kernel

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.

Signed-off-by: Maxim Devaev <mdevaev@gmail.com>
---
 drivers/usb/gadget/function/f_hid.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index 02683ac07..1010f0a3e 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -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;
@@ -523,6 +524,14 @@ 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);
@@ -546,6 +555,14 @@ 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 >> 8;
+		goto respond;
+		break;
+
 	case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 		  | USB_REQ_GET_DESCRIPTOR):
 		switch (value >> 8) {
@@ -773,6 +790,7 @@ 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);
-- 
2.32.0


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2021-07-27 19:00 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-27 18:31 [PATCH v2] usb: gadget: f_hid: added GET_IDLE and SET_IDLE handlers Maxim Devaev
2021-07-27 18:45 ` Greg KH
2021-07-27 18:46 ` Greg KH
2021-07-27 18:59   ` Maxim Devaev

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