[PATCH v4 01/11] HID: pidff: Convert infinite length from Linux API to PID standard
From: Tomasz Pakuła <tomasz.pakula.oficjalny@gmail.com>
Date: 2025-01-13 12:49:28
Also in:
linux-usb
Subsystem:
hid core layer, the rest, usb hid pid drivers (usb wheelbases, joysticks, rudders, ...), usb hid/hidbp drivers (usb keyboards, mice, remote controls, ...) · Maintainers:
Jiri Kosina, Benjamin Tissoires, Linus Torvalds, Tomasz Pakuła, Oleg Makarenko
Linux defines 0 length as infinite in its force feedback API while USB PID defines NULL (0xffff). Most PID devices do not expect a 0-length effect and can't interpret it as infinite. This change fixes Force Feedback for most PID compliant devices. As most games depend on updating the values of already playing infinite effects, this is crucial to ensure they will actually work. Previously, users had to rely on third-party software to do this conversion and make their PID devices usable. Co-developed-by: Makarenko Oleg <oleg@makarenk.ooo> Signed-off-by: Makarenko Oleg <oleg@makarenk.ooo> Signed-off-by: Tomasz Pakuła <tomasz.pakula.oficjalny@gmail.com> --- drivers/hid/usbhid/hid-pidff.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/hid/usbhid/hid-pidff.c b/drivers/hid/usbhid/hid-pidff.c
index 3b4ee21cd811..3899d72a0b02 100644
--- a/drivers/hid/usbhid/hid-pidff.c
+++ b/drivers/hid/usbhid/hid-pidff.c@@ -301,7 +301,12 @@ static void pidff_set_effect_report(struct pidff_device *pidff, pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0]; pidff->set_effect_type->value[0] = pidff->create_new_effect_type->value[0]; - pidff->set_effect[PID_DURATION].value[0] = effect->replay.length; + + // Convert infinite length from Linux API (0) + // to PID standard (NULL) if needed + pidff->set_effect[PID_DURATION].value[0] = + effect->replay.length == 0 ? 0xffff : effect->replay.length; + pidff->set_effect[PID_TRIGGER_BUTTON].value[0] = effect->trigger.button; pidff->set_effect[PID_TRIGGER_REPEAT_INT].value[0] = effect->trigger.interval;
--
2.48.0