HID: magicmouse: ignore 'ivalid report id' while switching modes

BugLink: http://bugs.launchpad.net/bugs/793702

commit 23746a66d7d9e73402c68ef00d708796b97ebd72 upstream.

The device reponds with 'invalid report id' when feature report switching it
into multitouch mode is sent to it.

This has been silently ignored before 0825411ade ("HID: bt: Wait for ACK
on Sent Reports"), but since this commit, it propagates -EIO from the _raw
callback .

So let the driver ignore -EIO as response to 0xd7,0x01 report, as that's
how the device reacts in normal mode.

Sad, but following reality.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=35022

Tested-by: Chase Douglas <chase.douglas@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/drivers/hid/hid-magicmouse.c b/drivers/hid/hid-magicmouse.c
index 418c399..a3972bb 100644 (file)
--- a/drivers/hid/hid-magicmouse.c
+++ b/drivers/hid/hid-magicmouse.c
@@ -501,9 +501,17 @@ static int magicmouse_probe(struct hid_device *hdev,
        }
        report->size = 6;
 
+       /*
+        * The device reponds with 'invalid report id' when feature
+        * report switching it into multitouch mode is sent to it.
+        *
+        * This results in -EIO from the _raw low-level transport callback,
+        * but there seems to be no other way of switching the mode.
+        * Thus the super-ugly hacky success check below.
+        */
        ret = hdev->hid_output_raw_report(hdev, feature, sizeof(feature),
                        HID_FEATURE_REPORT);
-       if (ret != sizeof(feature)) {
+       if (ret != -EIO) {
                hid_err(hdev, "unable to request touch data (%d)\n", ret);
                goto err_stop_hw;
        }