On Wed, Jun 21, 2023 at 5:18 PM Jason Gerecke <killertofu@xxxxxxxxx> wrote: > > Following up since no action seems to have been taken on this patch yet. Sorry, this went through the cracks (I seem to have a lot of cracks recently...) > > 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. I have to ask, is this something we should consider writing a test for? :) Also, you are missing the rev-by from Peter, not sure if the tools will pick it up automatically then. Reviewed-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> Cheers, Benjamin > > > > 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 > > >
