[PATCH] HID: magicmouse: Don't report REL_{X,Y} for Magic Trackpad

From: Chase Douglas <chase.douglas@canonical.com>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Michael Poole <mdpoole@troilus.org>,
	linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] HID: magicmouse: Don't report REL_{X,Y} for Magic Trackpad
Date: Wed,  8 Dec 2010 15:08:04 -0800	[thread overview]
Message-ID: <1291849685-2623-1-git-send-email-chase.douglas@canonical.com> (raw)

With the recent switch to having the hid layer handle standard axis
initialization, the Magic Trackpad now reports relative axes. This would
be fine in the normal mode, but the driver puts the device in multitouch
mode where no relative events are generated. Also, userspace software
depends on accurate axis information for device type detection. Thus,
ignoring the relative axes from the Magic Trackpad is best.

Signed-off-by: Chase Douglas <chase.douglas@canonical.com>
---
 drivers/hid/hid-magicmouse.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/hid/hid-magicmouse.c b/drivers/hid/hid-magicmouse.c
index e6dc151..ed732b7 100644
--- a/drivers/hid/hid-magicmouse.c
+++ b/drivers/hid/hid-magicmouse.c
@@ -433,6 +433,11 @@ static int magicmouse_input_mapping(struct hid_device *hdev,
 	if (!msc->input)
 		msc->input = hi->input;
 
+	/* Magic Trackpad does not give relative data after switching to MT */
+	if (hi->input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD &&
+	    field->flags & HID_MAIN_ITEM_RELATIVE)
+		return -1;
+
 	return 0;
 }
 
-- 
1.7.1

