Commit d43c17ea authored by Benjamin Tissoires's avatar Benjamin Tissoires
Browse files

HID: input: make sure the wheel high resolution multiplier is set 

Some old mice have a tendency to not accept the high resolution multiplier.
They reply with a -EPIPE which was previously ignored.

Force the call to resolution multiplier to be synchronous and actually
check for the answer. If this fails, consider the mouse like a normal one.

Fixes: 2dc702c9 ("HID: input: use the Resolution Multiplier for
       high-resolution scrolling")
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1700071


Reported-and-tested-by: default avatarJames Feeney <james@nurealm.net>
Cc: stable@vger.kernel.org  # v5.0+
Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
parent a50e8e2e

drivers/hid/hid-core.c

+5 −2
Original line number Diff line number Diff line
@@ -1624,7 +1624,7 @@ static struct hid_report *hid_get_report(struct hid_report_enum *report_enum, 
 * Implement a generic .request() callback, using .raw_request()

 * DO NOT USE in hid drivers directly, but through hid_hw_request instead.

 */

void __hid_request(struct hid_device *hid, struct hid_report *report,

int __hid_request(struct hid_device *hid, struct hid_report *report,

		int reqtype)

{

	char *buf;
@@ -1633,7 +1633,7 @@ void __hid_request(struct hid_device *hid, struct hid_report *report, 


	buf = hid_alloc_report_buf(report, GFP_KERNEL);

	if (!buf)

		return;

		return -ENOMEM;



	len = hid_report_len(report);
@@ -1650,8 +1650,11 @@ void __hid_request(struct hid_device *hid, struct hid_report *report, 
	if (reqtype == HID_REQ_GET_REPORT)

		hid_input_report(hid, report->type, buf, ret, 0);



	ret = 0;



out:

	kfree(buf);

	return ret;

}

EXPORT_SYMBOL_GPL(__hid_request);

drivers/hid/hid-input.c

+50 −31
Original line number Diff line number Diff line
@@ -1542,52 +1542,71 @@ static void hidinput_close(struct input_dev *dev) 
	hid_hw_close(hid);

}



static void hidinput_change_resolution_multipliers(struct hid_device *hid)

static bool __hidinput_change_resolution_multipliers(struct hid_device *hid,

		struct hid_report *report, bool use_logical_max)

{

	struct hid_report_enum *rep_enum;

	struct hid_report *rep;

	struct hid_usage *usage;

	int i, j;



	rep_enum = &hid->report_enum[HID_FEATURE_REPORT];

	list_for_each_entry(rep, &rep_enum->report_list, list) {

	bool update_needed = false;

	int i, j;



		if (rep->maxfield == 0)

			continue;

	if (report->maxfield == 0)

		return false;



	/*

	 * If we have more than one feature within this report we

	 * need to fill in the bits from the others before we can

	 * overwrite the ones for the Resolution Multiplier.

	 */

		if (rep->maxfield > 1) {

			hid_hw_request(hid, rep, HID_REQ_GET_REPORT);

	if (report->maxfield > 1) {

		hid_hw_request(hid, report, HID_REQ_GET_REPORT);

		hid_hw_wait(hid);

	}



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

			__s32 logical_max = rep->field[i]->logical_maximum;

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

		__s32 value = use_logical_max ?

			      report->field[i]->logical_maximum :

			      report->field[i]->logical_minimum;



		/* There is no good reason for a Resolution

		 * Multiplier to have a count other than 1.

		 * Ignore that case.

		 */

			if (rep->field[i]->report_count != 1)

		if (report->field[i]->report_count != 1)

			continue;



			for (j = 0; j < rep->field[i]->maxusage; j++) {

				usage = &rep->field[i]->usage[j];

		for (j = 0; j < report->field[i]->maxusage; j++) {

			usage = &report->field[i]->usage[j];



			if (usage->hid != HID_GD_RESOLUTION_MULTIPLIER)

				continue;



				*rep->field[i]->value = logical_max;

			*report->field[i]->value = value;

			update_needed = true;

		}

	}

		if (update_needed)

			hid_hw_request(hid, rep, HID_REQ_SET_REPORT);



	return update_needed;

}



static void hidinput_change_resolution_multipliers(struct hid_device *hid)

{

	struct hid_report_enum *rep_enum;

	struct hid_report *rep;

	int ret;



	rep_enum = &hid->report_enum[HID_FEATURE_REPORT];

	list_for_each_entry(rep, &rep_enum->report_list, list) {

		bool update_needed = __hidinput_change_resolution_multipliers(hid,

								     rep, true);



		if (update_needed) {

			ret = __hid_request(hid, rep, HID_REQ_SET_REPORT);

			if (ret) {

				__hidinput_change_resolution_multipliers(hid,

								    rep, false);

				return;

			}

		}

	}



	/* refresh our structs */

include/linux/hid.h

+1 −1
Original line number Diff line number Diff line
@@ -893,7 +893,7 @@ struct hid_field *hidinput_get_led_field(struct hid_device *hid); 
unsigned int hidinput_count_leds(struct hid_device *hid);

__s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code);

void hid_output_report(struct hid_report *report, __u8 *data);

void __hid_request(struct hid_device *hid, struct hid_report *rep, int reqtype);

int __hid_request(struct hid_device *hid, struct hid_report *rep, int reqtype);

u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags);

struct hid_device *hid_allocate_device(void);

struct hid_report *hid_register_report(struct hid_device *device,

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