Following up since no action seems to have been taken on this patch yet. On Thu, Jun 8, 2023 at 2:38 PM Jason Gerecke <killertofu@xxxxxxxxx> wrote: > > Code which interacts with timestamps needs to use the ktime_t type > returned by functions like ktime_get. The int type does not offer > enough space to store these values, and attempting to use it is a > recipe for problems. In this particular case, overflows would occur > when calculating/storing timestamps leading to incorrect values being > reported to userspace. In some cases these bad timestamps cause input > handling in userspace to appear hung. > > Link: https://gitlab.freedesktop.org/libinput/libinput/-/issues/901 > Fixes: 17d793f3ed53 ("HID: wacom: insert timestamp to packed Bluetooth (BT) events") > CC: stable@xxxxxxxxxxxxxxx > Signed-off-by: Jason Gerecke <jason.gerecke@xxxxxxxxx> > --- > v2: Use div_u64 to perform division to deal with ARC and ARM architectures > (as found by the kernel test robot) > > drivers/hid/wacom_wac.c | 6 +++--- > drivers/hid/wacom_wac.h | 2 +- > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c > index 2ccf838371343..174bf03908d7c 100644 > --- a/drivers/hid/wacom_wac.c > +++ b/drivers/hid/wacom_wac.c > @@ -1314,7 +1314,7 @@ static void wacom_intuos_pro2_bt_pen(struct wacom_wac *wacom) > struct input_dev *pen_input = wacom->pen_input; > unsigned char *data = wacom->data; > int number_of_valid_frames = 0; > - int time_interval = 15000000; > + ktime_t time_interval = 15000000; > ktime_t time_packet_received = ktime_get(); > int i; > > @@ -1348,7 +1348,7 @@ static void wacom_intuos_pro2_bt_pen(struct wacom_wac *wacom) > if (number_of_valid_frames) { > if (wacom->hid_data.time_delayed) > time_interval = ktime_get() - wacom->hid_data.time_delayed; > - time_interval /= number_of_valid_frames; > + time_interval = div_u64(time_interval, number_of_valid_frames); > wacom->hid_data.time_delayed = time_packet_received; > } > > @@ -1359,7 +1359,7 @@ static void wacom_intuos_pro2_bt_pen(struct wacom_wac *wacom) > bool range = frame[0] & 0x20; > bool invert = frame[0] & 0x10; > int frames_number_reversed = number_of_valid_frames - i - 1; > - int event_timestamp = time_packet_received - frames_number_reversed * time_interval; > + ktime_t event_timestamp = time_packet_received - frames_number_reversed * time_interval; > > if (!valid) > continue; > diff --git a/drivers/hid/wacom_wac.h b/drivers/hid/wacom_wac.h > index 1a40bb8c5810c..ee21bb260f22f 100644 > --- a/drivers/hid/wacom_wac.h > +++ b/drivers/hid/wacom_wac.h > @@ -324,7 +324,7 @@ struct hid_data { > int ps_connected; > bool pad_input_event_flag; > unsigned short sequence_number; > - int time_delayed; > + ktime_t time_delayed; > }; > > struct wacom_remote_data { > -- > 2.41.0 >
