[ 07/64] HID: magicmouse: fix race between input_register() and probe()
From: Greg Kroah-Hartman
Date: Wed Apr 10 2013 - 19:15:10 EST
3.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
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 <cwixon@xxxxxxx>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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)
--
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