From f1a9a149abc86903e81dd1b2e720f3f89874384b Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Tue, 2 Apr 2013 11:11:52 +0200 Subject: HID: magicmouse: fix race between input_register() and probe() From: Benjamin Tissoires commit f1a9a149abc86903e81dd1b2e720f3f89874384b upstream. Since kernel 3.7, it appears that the input registration occured before the end of magicmouse_setup_input(). This is shown by receiving a lot of "EV_SYN SYN_REPORT 1" instead of normal "EV_SYN SYN_REPORT 0". This value means that the output buffer is full, and the user space is loosing events. Using .input_configured guarantees that the race is not occuring, and that the call of "input_set_events_per_packet(input, 60)" is taken into account by input_register(). Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=908604 Reported-and-Tested-By: Clarke Wixon Signed-off-by: Benjamin Tissoires Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hid-magicmouse.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) --- a/drivers/hid/hid-magicmouse.c +++ b/drivers/hid/hid-magicmouse.c @@ -462,6 +462,21 @@ static int magicmouse_input_mapping(stru return 0; } +static void magicmouse_input_configured(struct hid_device *hdev, + struct hid_input *hi) + +{ + struct magicmouse_sc *msc = hid_get_drvdata(hdev); + + int ret = magicmouse_setup_input(msc->input, hdev); + if (ret) { + hid_err(hdev, "magicmouse setup input failed (%d)\n", ret); + /* clean msc->input to notify probe() of the failure */ + msc->input = NULL; + } +} + + static int magicmouse_probe(struct hid_device *hdev, const struct hid_device_id *id) { @@ -493,15 +508,10 @@ static int magicmouse_probe(struct hid_d goto err_free; } - /* We do this after hid-input is done parsing reports so that - * hid-input uses the most natural button and axis IDs. - */ - if (msc->input) { - ret = magicmouse_setup_input(msc->input, hdev); - if (ret) { - hid_err(hdev, "magicmouse setup input failed (%d)\n", ret); - goto err_stop_hw; - } + if (!msc->input) { + hid_err(hdev, "magicmouse input not registered\n"); + ret = -ENOMEM; + goto err_stop_hw; } if (id->product == USB_DEVICE_ID_APPLE_MAGICMOUSE) @@ -568,6 +578,7 @@ static struct hid_driver magicmouse_driv .remove = magicmouse_remove, .raw_event = magicmouse_raw_event, .input_mapping = magicmouse_input_mapping, + .input_configured = magicmouse_input_configured, }; static int __init magicmouse_init(void)