1 files changed, 44 insertions, 1 deletions

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 661b4fce1a5d..dd64461e5e85 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -309,6 +309,41 @@ static struct attribute_group mt_attribute_group = {
         .attrs = sysfs_attrs
 };
 
+static void mt_get_feature(struct hid_device *hdev, struct hid_report *report)
+{
+        struct mt_device *td = hid_get_drvdata(hdev);
+        int ret, size = hid_report_len(report);
+        u8 *buf;
+
+        /*
+         * Only fetch the feature report if initial reports are not already
+         * been retrieved. Currently this is only done for Windows 8 touch
+         * devices.
+         */
+        if (!(hdev->quirks & HID_QUIRK_NO_INIT_REPORTS))
+                return;
+        if (td->mtclass.name != MT_CLS_WIN_8)
+                return;
+
+        buf = hid_alloc_report_buf(report, GFP_KERNEL);
+        if (!buf)
+                return;
+
+        ret = hid_hw_raw_request(hdev, report->id, buf, size,
+                                 HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
+        if (ret < 0) {
+                dev_warn(&hdev->dev, "failed to fetch feature %d\n",
+                         report->id);
+        } else {
+                ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, buf,
+                                           size, 0);
+                if (ret)
+                        dev_warn(&hdev->dev, "failed to report feature\n");
+        }
+
+        kfree(buf);
+}
+
 static void mt_feature_mapping(struct hid_device *hdev,
                 struct hid_field *field, struct hid_usage *usage)
 {
@@ -327,6 +362,8 @@ static void mt_feature_mapping(struct hid_device *hdev,
 
                 break;
         case HID_DG_CONTACTMAX:
+                mt_get_feature(hdev, field->report);
+
                 td->maxcontact_report_id = field->report->id;
                 td->maxcontacts = field->value[0];
                 if (!td->maxcontacts &&
@@ -343,6 +380,7 @@ static void mt_feature_mapping(struct hid_device *hdev,
                         break;
                 }
 
+                mt_get_feature(hdev, field->report);
                 if (field->value[usage->usage_index] == MT_BUTTONTYPE_CLICKPAD)
                         td->is_buttonpad = true;
 
@@ -1029,8 +1067,13 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
                  * reports. Fortunately, the Win8 spec says that all touches
                  * should be sent during each report, making the initialization
                  * of input reports unnecessary.
+                 *
+                 * In addition some touchpads do not behave well if we read
+                 * all feature reports from them. Instead we prevent
+                 * initial report fetching and then selectively fetch each
+                 * report we are interested in.
                  */
-                hdev->quirks |= HID_QUIRK_NO_INIT_INPUT_REPORTS;
+                hdev->quirks |= HID_QUIRK_NO_INIT_REPORTS;
 
         td = devm_kzalloc(&hdev->dev, sizeof(struct mt_device), GFP_KERNEL);
         if (!td) {