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usb: gadget: f_hid: added GET_IDLE and SET_IDLE handlers

PATCH In review Maxim Devaev 2 participants 4 messages Jul 27, 2021 USB

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#0 lore raw

PATCH v2 1/1 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.

---
 drivers/usb/gadget/function/f_hid.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
drivers/usb/gadget/function/f_hid.c +18 -0
index 02683ac07..1010f0a3e 100644
@@ -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);
Signature · 1 line
2.32.0
maintainer
#1 lore raw
Quoted 66 lines · Maxim Devaev

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.

---
 drivers/usb/gadget/function/f_hid.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
drivers/usb/gadget/function/f_hid.c +18 -0
index 02683ac07..1010f0a3e 100644
@@ -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);
Signature · 1 line
2.32.0

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him a patch that has triggered this response. He used to manually respond to these common problems, but in order to save his sanity (he kept writing the same thing over and over, yet to different people), I was created. Hopefully you will not take offence and will fix the problem in your patch and resubmit it so that it can be accepted into the Linux kernel tree.

You are receiving this message because of the following common error(s) as indicated below:

- You sent a patch that has been sent multiple times in the past few days, and is identical to ones that has been recently rejected. Please always look at the mailing list traffic to determine if you are duplicating other people's work.

If you wish to discuss this problem further, or you have questions about how to resolve this issue, please feel free to respond to this email and Greg will reply once he has dug out from the pending patches received from other developers.

thanks,

greg k-h's patch email bot

maintainer
#2 lore raw
In reply to Maxim Devaev
Quoted 5 lines · Maxim Devaev

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.

Quoted 7 lines

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

---
 drivers/usb/gadget/function/f_hid.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

As I already took your first patch, and I can not drop it as it is a public tree, can you just send me the fixup patch? That would be simpler than me reverting the original and then applying a "fixed" version, right?

thanks,

greg k-h

#3 lore raw
Quoted 5 lines

Greg KH <[email protected]> wrote:
As I already took your first patch, and I can not drop it as it is a public tree, can you just send me the fixup patch? That would be simpler than me reverting the original and then applying a "fixed" version, right?

Sure. Sent a fix as ("usb: gadget: f_hid: idle uses the highest byte for duration").