diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c index 518ccf15188e..26c7701fb188 100644 --- a/drivers/hid/i2c-hid/i2c-hid-core.c +++ b/drivers/hid/i2c-hid/i2c-hid-core.c @@ -643,6 +643,17 @@ static int i2c_hid_get_raw_report(struct hid_device *hid, if (report_type == HID_OUTPUT_REPORT) return -EINVAL; + /* + * In case of unnumbered reports the response from the device will + * not have the report ID that the upper layers expect, so we need + * to stash it the buffer ourselves and adjust the data size. + */ + if (!report_number) { + buf[0] = 0; + buf++; + count--; + } + /* +2 bytes to include the size of the reply in the query buffer */ ask_count = min(count + 2, (size_t)ihid->bufsize); @@ -664,6 +675,9 @@ static int i2c_hid_get_raw_report(struct hid_device *hid, count = min(count, ret_count - 2); memcpy(buf, ihid->rawbuf + 2, count); + if (!report_number) + count++; + return count; } @@ -680,17 +694,19 @@ static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf, mutex_lock(&ihid->reset_lock); - if (report_id) { - buf++; - count--; - } - + /* + * Note that both numbered and unnumbered reports passed here + * are supposed to have report ID stored in the 1st byte of the + * buffer, so we strip it off unconditionally before passing payload + * to i2c_hid_set_or_send_report which takes care of encoding + * everything properly. + */ ret = i2c_hid_set_or_send_report(client, report_type == HID_FEATURE_REPORT ? 0x03 : 0x02, - report_id, buf, count, use_data); + report_id, buf + 1, count - 1, use_data); - if (report_id && ret >= 0) - ret++; /* add report_id to the number of transfered bytes */ + if (ret >= 0) + ret++; /* add report_id to the number of transferred bytes */ mutex_unlock(&ihid->reset_lock);