Commit 4f22decf authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Jiri Kosina
Browse files

HID: input: don't register unmapped input devices 



There is no need to register an input device containing no events.
This allows drivers using the quirk MULTI_INPUT to register one input
per report effectively used.

For backward compatibility, we need to add a quirk to request
this behavior.

Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent b3fecf8c

drivers/hid/hid-input.c

+77 −0
Original line number Diff line number Diff line
@@ -1198,6 +1198,67 @@ static struct hid_input *hidinput_allocate(struct hid_device *hid) 
	return hidinput;

}



static bool hidinput_has_been_populated(struct hid_input *hidinput)

{

	int i;

	unsigned long r = 0;



	for (i = 0; i < BITS_TO_LONGS(EV_CNT); i++)

		r |= hidinput->input->evbit[i];



	for (i = 0; i < BITS_TO_LONGS(KEY_CNT); i++)

		r |= hidinput->input->keybit[i];



	for (i = 0; i < BITS_TO_LONGS(REL_CNT); i++)

		r |= hidinput->input->relbit[i];



	for (i = 0; i < BITS_TO_LONGS(ABS_CNT); i++)

		r |= hidinput->input->absbit[i];



	for (i = 0; i < BITS_TO_LONGS(MSC_CNT); i++)

		r |= hidinput->input->mscbit[i];



	for (i = 0; i < BITS_TO_LONGS(LED_CNT); i++)

		r |= hidinput->input->ledbit[i];



	for (i = 0; i < BITS_TO_LONGS(SND_CNT); i++)

		r |= hidinput->input->sndbit[i];



	for (i = 0; i < BITS_TO_LONGS(FF_CNT); i++)

		r |= hidinput->input->ffbit[i];



	for (i = 0; i < BITS_TO_LONGS(SW_CNT); i++)

		r |= hidinput->input->swbit[i];



	return !!r;

}



static void hidinput_cleanup_hidinput(struct hid_device *hid,

		struct hid_input *hidinput)

{

	struct hid_report *report;

	int i, k;



	list_del(&hidinput->list);

	input_free_device(hidinput->input);



	for (k = HID_INPUT_REPORT; k <= HID_OUTPUT_REPORT; k++) {

		if (k == HID_OUTPUT_REPORT &&

			hid->quirks & HID_QUIRK_SKIP_OUTPUT_REPORTS)

			continue;



		list_for_each_entry(report, &hid->report_enum[k].report_list,

				    list) {



			for (i = 0; i < report->maxfield; i++)

				if (report->field[i]->hidinput == hidinput)

					report->field[i]->hidinput = NULL;

		}

	}



	kfree(hidinput);

}



/*

 * Register the input device; print a message.

 * Configure the input layer interface
@@ -1249,6 +1310,10 @@ int hidinput_connect(struct hid_device *hid, unsigned int force) 
					hidinput_configure_usage(hidinput, report->field[i],

								 report->field[i]->usage + j);



			if ((hid->quirks & HID_QUIRK_NO_EMPTY_INPUT) &&

			    !hidinput_has_been_populated(hidinput))

				continue;



			if (hid->quirks & HID_QUIRK_MULTI_INPUT) {

				/* This will leave hidinput NULL, so that it

				 * allocates another one if we have more inputs on
@@ -1265,6 +1330,18 @@ int hidinput_connect(struct hid_device *hid, unsigned int force) 
		}

	}



	if (hidinput && (hid->quirks & HID_QUIRK_NO_EMPTY_INPUT) &&

	    !hidinput_has_been_populated(hidinput)) {

		/* no need to register an input device not populated */

		hidinput_cleanup_hidinput(hid, hidinput);

		hidinput = NULL;

	}



	if (list_empty(&hid->inputs)) {

		hid_err(hid, "No inputs registered, leaving\n");

		goto out_unwind;

	}



	if (hidinput) {

		if (drv->input_configured)

			drv->input_configured(hid, hidinput);

include/linux/hid.h

+1 −0
Original line number Diff line number Diff line
@@ -282,6 +282,7 @@ struct hid_item { 
#define HID_QUIRK_BADPAD			0x00000020

#define HID_QUIRK_MULTI_INPUT			0x00000040

#define HID_QUIRK_HIDINPUT_FORCE		0x00000080

#define HID_QUIRK_NO_EMPTY_INPUT		0x00000100

#define HID_QUIRK_SKIP_OUTPUT_REPORTS		0x00010000

#define HID_QUIRK_FULLSPEED_INTERVAL		0x10000000

#define HID_QUIRK_NO_INIT_REPORTS		0x20000000