Merge branch 'fixes-rc2' into fixes

1 files changed, 25 insertions, 1 deletions

diff --git a/drivers/virtio/virtio_input.c b/drivers/virtio/virtio_input.c
index f1f6208edcf5..ce51ae165943 100644
--- a/drivers/virtio/virtio_input.c
+++ b/drivers/virtio/virtio_input.c
@@ -7,6 +7,7 @@
 
 #include <uapi/linux/virtio_ids.h>
 #include <uapi/linux/virtio_input.h>
+#include <linux/input/mt.h>
 
 struct virtio_input {
 	struct virtio_device       *vdev;
@@ -64,6 +65,21 @@ static int virtinput_send_status(struct virtio_input *vi,
 	unsigned long flags;
 	int rc;
 
+	/*
+	 * Since 29cc309d8bf1 (HID: hid-multitouch: forward MSC_TIMESTAMP),
+	 * EV_MSC/MSC_TIMESTAMP is added to each before EV_SYN event.
+	 * EV_MSC is configured as INPUT_PASS_TO_ALL.
+	 * In case of touch device:
+	 *   BE pass EV_MSC/MSC_TIMESTAMP to FE on receiving event from evdev.
+	 *   FE pass EV_MSC/MSC_TIMESTAMP back to BE.
+	 *   BE writes EV_MSC/MSC_TIMESTAMP to evdev due to INPUT_PASS_TO_ALL.
+	 *   BE receives extra EV_MSC/MSC_TIMESTAMP and pass to FE.
+	 *   >>> Each new frame becomes larger and larger.
+	 * Disable EV_MSC/MSC_TIMESTAMP forwarding for MT.
+	 */
+	if (vi->idev->mt && type == EV_MSC && code == MSC_TIMESTAMP)
+		return 0;
+
 	stsbuf = kzalloc(sizeof(*stsbuf), GFP_ATOMIC);
 	if (!stsbuf)
 		return -ENOMEM;
@@ -204,7 +220,7 @@ static int virtinput_probe(struct virtio_device *vdev)
 	struct virtio_input *vi;
 	unsigned long flags;
 	size_t size;
-	int abs, err;
+	int abs, err, nslots;
 
 	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
 		return -ENODEV;
@@ -289,6 +305,13 @@ static int virtinput_probe(struct virtio_device *vdev)
 				continue;
 			virtinput_cfg_abs(vi, abs);
 		}
+
+		if (test_bit(ABS_MT_SLOT, vi->idev->absbit)) {
+			nslots = input_abs_get_max(vi->idev, ABS_MT_SLOT) + 1;
+			err = input_mt_init_slots(vi->idev, nslots, 0);
+			if (err)
+				goto err_mt_init_slots;
+		}
 	}
 
 	virtio_device_ready(vdev);
@@ -304,6 +327,7 @@ err_input_register:
 	spin_lock_irqsave(&vi->lock, flags);
 	vi->ready = false;
 	spin_unlock_irqrestore(&vi->lock, flags);
+err_mt_init_slots:
 	input_free_device(vi->idev);
 err_input_alloc:
 	vdev->config->del_vqs(vdev);