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path: root/drivers/virtio/virtio_input.c
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Diffstat (limited to 'drivers/virtio/virtio_input.c')
-rw-r--r--drivers/virtio/virtio_input.c26
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);