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Commit 8c9952b2 authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Jiri Kosina
Browse files

HID: logitech-hidpp: fix negated returns 



Reported by Dan Carpenter:

drivers/hid/hid-logitech-hidpp.c:359 hidpp_root_get_protocol_version() warn: should this return really be negated?
drivers/hid/hid-logitech-hidpp.c:398 hidpp_devicenametype_get_count() warn: should this return really be negated?
drivers/hid/hid-logitech-hidpp.c:417 hidpp_devicenametype_get_device_name() warn: should this return really be negated?
drivers/hid/hid-logitech-hidpp.c:524 hidpp_touchpad_get_raw_info() warn: should this return really be negated?

The problem lies in hidpp_send_message_sync() which can return 2 types of
errors depending of their sign. Adding a comment there to clarify what is
happening.

To solve that, print an error in case of a protocol problem, and raise
-EPROTO instead.

Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 3e7830ce

drivers/hid/hid-logitech-hidpp.c

+32 −4
Original line number Original line Diff line number Diff line
@@ -151,6 +151,14 @@ static int __hidpp_send_report(struct hid_device *hdev, 
	return ret == fields_count ? 0 : -1;

	return ret == fields_count ? 0 : -1;

}

}





/**

 * hidpp_send_message_sync() returns 0 in case of success, and something else

 * in case of a failure.

 * - If ' something else' is positive, that means that an error has been raised

 *   by the protocol itself.

 * - If ' something else' is negative, that means that we had a classic error

 *   (-ENOMEM, -EPIPE, etc...)

 */

static int hidpp_send_message_sync(struct hidpp_device *hidpp,

static int hidpp_send_message_sync(struct hidpp_device *hidpp,

	struct hidpp_report *message,

	struct hidpp_report *message,

	struct hidpp_report *response)

	struct hidpp_report *response)
@@ -359,8 +367,13 @@ static int hidpp_root_get_protocol_version(struct hidpp_device *hidpp) 
		return 0;

		return 0;

	}

	}





	if (ret > 0) {

		hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",

			__func__, ret);

		return -EPROTO;

	}

	if (ret)

	if (ret)

		return -ret;

		return ret;





	hidpp->protocol_major = response.fap.params[0];

	hidpp->protocol_major = response.fap.params[0];

	hidpp->protocol_minor = response.fap.params[1];

	hidpp->protocol_minor = response.fap.params[1];
@@ -398,8 +411,13 @@ static int hidpp_devicenametype_get_count(struct hidpp_device *hidpp, 
	ret = hidpp_send_fap_command_sync(hidpp, feature_index,

	ret = hidpp_send_fap_command_sync(hidpp, feature_index,

		CMD_GET_DEVICE_NAME_TYPE_GET_COUNT, NULL, 0, &response);

		CMD_GET_DEVICE_NAME_TYPE_GET_COUNT, NULL, 0, &response);





	if (ret > 0) {

		hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",

			__func__, ret);

		return -EPROTO;

	}

	if (ret)

	if (ret)

		return -ret;

		return ret;





	*nameLength = response.fap.params[0];

	*nameLength = response.fap.params[0];
@@ -417,8 +435,13 @@ static int hidpp_devicenametype_get_device_name(struct hidpp_device *hidpp, 
		CMD_GET_DEVICE_NAME_TYPE_GET_DEVICE_NAME, &char_index, 1,

		CMD_GET_DEVICE_NAME_TYPE_GET_DEVICE_NAME, &char_index, 1,

		&response);

		&response);





	if (ret > 0) {

		hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",

			__func__, ret);

		return -EPROTO;

	}

	if (ret)

	if (ret)

		return -ret;

		return ret;





	if (response.report_id == REPORT_ID_HIDPP_LONG)

	if (response.report_id == REPORT_ID_HIDPP_LONG)

		count = HIDPP_REPORT_LONG_LENGTH - 4;

		count = HIDPP_REPORT_LONG_LENGTH - 4;
@@ -524,8 +547,13 @@ static int hidpp_touchpad_get_raw_info(struct hidpp_device *hidpp, 
	ret = hidpp_send_fap_command_sync(hidpp, feature_index,

	ret = hidpp_send_fap_command_sync(hidpp, feature_index,

		CMD_TOUCHPAD_GET_RAW_INFO, NULL, 0, &response);

		CMD_TOUCHPAD_GET_RAW_INFO, NULL, 0, &response);





	if (ret > 0) {

		hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",

			__func__, ret);

		return -EPROTO;

	}

	if (ret)

	if (ret)

		return -ret;

		return ret;





	raw_info->x_size = get_unaligned_be16(&params[0]);

	raw_info->x_size = get_unaligned_be16(&params[0]);

	raw_info->y_size = get_unaligned_be16(&params[2]);

	raw_info->y_size = get_unaligned_be16(&params[2]);