Commit 3fe6acd4 authored by Dmitry Torokhov's avatar Dmitry Torokhov Committed by Jiri Kosina
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HID: vivaldi: fix handling devices not using numbered reports 



Unfortunately details of USB HID transport bled into HID core and
handling of numbered/unnumbered reports is quite a mess, with
hid_report_len() calculating the length according to USB rules,
and hid_hw_raw_request() adding report ID to the buffer for both
numbered and unnumbered reports.

Untangling it all requres a lot of changes in HID, so for now let's
handle this in the driver.

[jkosina@suse.cz: microoptimize field->report->id to report->id]
Fixes: 14c9c014 ("HID: add vivaldi HID driver")
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Stephen Boyd <swboyd@chromium.org> # CoachZ
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent f3193ea1

drivers/hid/hid-vivaldi.c

+28 −6
Original line number Diff line number Diff line
@@ -74,10 +74,11 @@ static void vivaldi_feature_mapping(struct hid_device *hdev, 
				    struct hid_usage *usage)

{

	struct vivaldi_data *drvdata = hid_get_drvdata(hdev);

	struct hid_report *report = field->report;

	int fn_key;

	int ret;

	u32 report_len;

	u8 *buf;

	u8 *report_data, *buf;



	if (field->logical != HID_USAGE_FN_ROW_PHYSMAP ||

	    (usage->hid & HID_USAGE_PAGE) != HID_UP_ORDINAL)
@@ -89,12 +90,24 @@ static void vivaldi_feature_mapping(struct hid_device *hdev, 
	if (fn_key > drvdata->max_function_row_key)

		drvdata->max_function_row_key = fn_key;



	buf = hid_alloc_report_buf(field->report, GFP_KERNEL);

	if (!buf)

	report_data = buf = hid_alloc_report_buf(report, GFP_KERNEL);

	if (!report_data)

		return;



	report_len = hid_report_len(field->report);

	ret = hid_hw_raw_request(hdev, field->report->id, buf,

	report_len = hid_report_len(report);

	if (!report->id) {

		/*

		 * hid_hw_raw_request() will stuff report ID (which will be 0)

		 * into the first byte of the buffer even for unnumbered

		 * reports, so we need to account for this to avoid getting

		 * -EOVERFLOW in return.

		 * Note that hid_alloc_report_buf() adds 7 bytes to the size

		 * so we can safely say that we have space for an extra byte.

		 */

		report_len++;

	}



	ret = hid_hw_raw_request(hdev, report->id, report_data,

				 report_len, HID_FEATURE_REPORT,

				 HID_REQ_GET_REPORT);

	if (ret < 0) {
@@ -103,7 +116,16 @@ static void vivaldi_feature_mapping(struct hid_device *hdev, 
		goto out;

	}



	ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, buf,

	if (!report->id) {

		/*

		 * Undo the damage from hid_hw_raw_request() for unnumbered

		 * reports.

		 */

		report_data++;

		report_len--;

	}



	ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, report_data,

				   report_len, 0);

	if (ret) {

		dev_warn(&hdev->dev, "failed to report feature %d\n",