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HID: magicmouse: fix race between input_register() and probe() 

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

Cc: stable@vger.kernel.org
Reported-and-Tested-By: Clarke Wixon <cwixon@usa.net>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
hifive-unleashed-5.1
Benjamin Tissoires 2013-04-02 11:11:52 +02:00 committed by Jiri Kosina
parent 30b29537bc
commit f1a9a149ab
1 changed files with 20 additions and 9 deletions
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29
drivers/hid/hid-magicmouse.c
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@ -462,6 +462,21 @@ static int magicmouse_input_mapping(struct hid_device *hdev,
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_device *hdev,
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_driver = {
.remove = magicmouse_remove,
.raw_event = magicmouse_raw_event,
.input_mapping = magicmouse_input_mapping,
.input_configured = magicmouse_input_configured,
};
module_hid_driver(magicmouse_driver);