[PATCH] USB: magicmouse: Make Magic Trackpad 2 to work after sleep/wake cycle

[PATCH] USB: magicmouse: Make Magic Trackpad 2 to work after sleep/wake cycle

[Daniel Turton]

The hid-magicmouse driver is not handling the Apple Magic Trackpad 2 device properly after a sleep/wake session, where single clicks were recognized, but mouse movement and other clicks were not. The remedy has been to remove and re-connect the device, allowing it to work once again.  More background on the issue is available here: https://github.com/robotrovsky/Linux-Magic-Trackpad-2-Driver/issues/37

This patch allows the device to operate properly after a sleep/wake session, but it returns a -32 (broken pipe) error code with the call to hid_hw_raw_request within the magicmouse_hdev_resume function below. In the original code, the prior developer(s) commented that some trackpads will send back an I/O error, and account for that in the if test below the hid_hw_raw_request call.

At this time, I'm not sure why the -32 error is being returned. I'm continuing the search on my end, but any assistance or pointers would be appreciated.

--- /home/dturton/kernel_hacking/linux/drivers/hid/hid-magicmouse.c 2019-11-24 16:28:11.150005796 -0600
+++ /home/dturton/kernel_hacking/magic_trackpad2_fix/linux/drivers/hid/hid-magicmouse.c 2019-11-26 10:37:14.450633946 -0600
@@ -700,6 +700,54 @@
  };
  MODULE_DEVICE_TABLE(hid, magic_mice);

+static int magicmouse_hdev_resume(struct hid_device *hdev)
+{
+    int ret;
+    int feature_size;
+    u8 *buf;
+    const u8 *feature;
+    const u8 feature_mt[] = { 0xD7, 0x01 };
+    const u8 feature_mt_trackpad2_usb[] = { 0x02, 0x01 };
+    const u8 feature_mt_trackpad2_bt[] = { 0xF1, 0x02, 0x01 };
+
+    if (hdev->product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
+        if (hdev->vendor == BT_VENDOR_ID_APPLE) {
+            feature_size = sizeof(feature_mt_trackpad2_bt);
+            feature = feature_mt_trackpad2_bt;
+        } else { /* USB_VENDOR_ID_APPLE */
+            feature_size = sizeof(feature_mt_trackpad2_usb);
+            feature = feature_mt_trackpad2_usb;
+        }
+    } else {
+        feature_size = sizeof(feature_mt);
+        feature = feature_mt;
+    }
+
+    buf = kmemdup(feature, feature_size, GFP_KERNEL);
+    if (!buf) {
+        ret = -ENOMEM;
+        goto err_stop_hw;
+    }
+
+    ret = hid_hw_raw_request(hdev, buf[0], buf, feature_size,
+                HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
+    kfree(buf);
+    if (ret != -EIO && ret != feature_size) {
+        hid_err(hdev, "unable to request touch data (%d)\n", ret);
+        goto err_stop_hw;
+    }
+    return 0;
+    err_stop_hw:
+            hid_hw_stop(hdev);
+            return ret;
+    }
+
+static int magicmouse_hdev_suspend(
+    struct hid_device *hdev,
+    struct pm_message ignored
+){
+    return 0;
+}
  static struct hid_driver magicmouse_driver = {
      .name = "magicmouse",
      .id_table = magic_mice,
@@ -707,6 +755,8 @@
      .raw_event = magicmouse_raw_event,
      .input_mapping = magicmouse_input_mapping,
      .input_configured = magicmouse_input_configured,
+    .reset_resume = magicmouse_hdev_resume,
+    .suspend = magicmouse_hdev_suspend,
  };
  module_hid_driver(magicmouse_driver);