refactor effect length calculation

- do the calculation in only one place
- avoid losing 1 ms (if it ever matters)

1 files changed, 21 insertions, 12 deletions

diff --git a/src/tmt300rs/hid-tmt300rs.c b/src/tmt300rs/hid-tmt300rs.c
index f83e3af..993b438 100644
--- a/src/tmt300rs/hid-tmt300rs.c
+++ b/src/tmt300rs/hid-tmt300rs.c
@@ -335,6 +335,15 @@ static u8 condition_values[] = {
 	0xff, 0xfe, 0xff
 };
 
+static uint16_t t300rs_calculate_length(uint16_t length)
+{
+	/* translate infinite effect length from Linux's 0 to the wheel's 0xffff */
+	if (length == 0)
+		return 0xffff;
+
+	return length;
+}
+
 static int16_t t300rs_calculate_constant_level(int16_t level, uint16_t direction)
 {
 	level = (level * fixp_sin16(direction * 360 / 0x10000)) / 0x7fff;
@@ -582,8 +591,8 @@ static int t300rs_update_constant(struct t300rs_device_entry *t300rs,
 	level = t300rs_calculate_constant_level(constant.level, effect.direction);
 	old_level = t300rs_calculate_constant_level(constant_old.level, old.direction);
 
-	length = effect.replay.length - 1;
-	old_length = old.replay.length - 1;
+	length = t300rs_calculate_length(effect.replay.length);
+	old_length = t300rs_calculate_length(old.replay.length);
 
 	if (!t300rs_is_envelope_changed(&constant.envelope, &constant_old.envelope)
 			&& level == old_level
@@ -637,8 +646,8 @@ static int t300rs_update_ramp(struct t300rs_device_entry *t300rs,
 	t300rs_calculate_ramp_parameters(&slope, &center, &invert, &effect);
 	t300rs_calculate_ramp_parameters(&old_slope, &old_center, &old_invert, &old);
 
-	length = effect.replay.length - 1;
-	old_length = old.replay.length - 1;
+	length = t300rs_calculate_length(effect.replay.length);
+	old_length = t300rs_calculate_length(old.replay.length);
 
 	if (!t300rs_is_envelope_changed(&ramp.envelope, &ramp_old.envelope)
 			&& slope == old_slope
@@ -713,8 +722,8 @@ static int t300rs_update_condition(struct t300rs_device_entry *t300rs,
 	left_sat = t300rs_calculate_saturation(cond.left_saturation, effect.type);
 	left_sat_old = t300rs_calculate_saturation(cond_old.left_saturation, old.type);
 
-	duration = effect.replay.length - 1;
-	duration_old = old.replay.length - 1;
+	duration = t300rs_calculate_length(effect.replay.length);
+	duration_old = t300rs_calculate_length(old.replay.length);
 
 	if (right_coeff == right_coeff_old
 			&& left_coeff == left_coeff_old
@@ -775,8 +784,8 @@ static int t300rs_update_periodic(struct t300rs_device_entry *t300rs,
 	t300rs_calculate_periodic_values(&old);
 	periodic_old = old.u.periodic;
 
-	length = effect.replay.length - 1;
-	old_length = old.replay.length - 1;
+	length = t300rs_calculate_length(effect.replay.length);
+	old_length = t300rs_calculate_length(old.replay.length);
 
 	if (!t300rs_is_envelope_changed(&periodic.envelope, &periodic_old.envelope)
 			&& periodic.magnitude == periodic_old.magnitude
@@ -827,7 +836,7 @@ static int t300rs_upload_constant(struct t300rs_device_entry *t300rs,
 	int ret;
 
 	level = t300rs_calculate_constant_level(constant.level, effect.direction);
-	duration = effect.replay.length - 1;
+	duration = t300rs_calculate_length(effect.replay.length);
 
 	offset = effect.replay.delay;
 
@@ -869,7 +878,7 @@ static int t300rs_upload_ramp(struct t300rs_device_entry *t300rs,
 
 	t300rs_calculate_ramp_parameters(&slope, &center, &invert, &effect);
 
-	duration = effect.replay.length - 1;
+	duration = t300rs_calculate_length(effect.replay.length);
 	offset = effect.replay.delay;
 
 	t300rs_fill_header(&packet_ramp->header, effect.id, 0x6b);
@@ -926,7 +935,7 @@ static int t300rs_upload_condition(struct t300rs_device_entry *t300rs,
 	right_sat = t300rs_calculate_saturation(cond.right_saturation, effect.type);
 	left_sat = t300rs_calculate_saturation(cond.left_saturation, effect.type);
 
-	duration = effect.replay.length - 1;
+	duration = t300rs_calculate_length(effect.replay.length);
 
 	offset = effect.replay.delay;
 
@@ -980,7 +989,7 @@ static int t300rs_upload_periodic(struct t300rs_device_entry *t300rs,
 
 	t300rs_calculate_periodic_values(&effect);
 	periodic = effect.u.periodic;
-	duration = effect.replay.length;
+	duration = t300rs_calculate_length(effect.replay.length);
 	offset = effect.replay.delay;
 	magnitude = periodic.magnitude;
 	period = periodic.period;