From: Tomasz Pakuła Date: Tue, 3 Feb 2026 17:45:28 +0000 (+0100) Subject: HID: pidff: Add MISSING_NEG_COEFFICIENT quirk X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=cf3bf7ad4e7722735d085b5fd5ab90a01be831d4;p=thirdparty%2Fkernel%2Flinux.git HID: pidff: Add MISSING_NEG_COEFFICIENT quirk Windows/Directinput allows devices with missing negative coefficient for conditional effects. Negative coefficient is ignored in such cases. Donot fail set_condition usage search if negative coefficient is missing. Fixes conditional effect playback on Asetek wheelbases. https://learn.microsoft.com/en-us/previous-versions/windows/desktop/ee416601(v=vs.85) Co-developed-by: Oleg Makarenko Signed-off-by: Oleg Makarenko Signed-off-by: Tomasz Pakuła Signed-off-by: Jiri Kosina --- diff --git a/drivers/hid/usbhid/hid-pidff.c b/drivers/hid/usbhid/hid-pidff.c index 68049d5d76b3d..aebf6c89643f7 100644 --- a/drivers/hid/usbhid/hid-pidff.c +++ b/drivers/hid/usbhid/hid-pidff.c @@ -619,8 +619,12 @@ static void pidff_set_condition_report(struct pidff_device *pidff, effect->u.condition[i].center); pidff_set_signed(&pidff->set_condition[PID_POS_COEFFICIENT], effect->u.condition[i].right_coeff); - pidff_set_signed(&pidff->set_condition[PID_NEG_COEFFICIENT], - effect->u.condition[i].left_coeff); + + /* Omit Negative Coefficient if missing */ + if (!(pidff->quirks & HID_PIDFF_QUIRK_MISSING_NEG_COEFFICIENT)) + pidff_set_signed(&pidff->set_condition[PID_NEG_COEFFICIENT], + effect->u.condition[i].left_coeff); + pidff_set(&pidff->set_condition[PID_POS_SATURATION], effect->u.condition[i].right_saturation); pidff_set(&pidff->set_condition[PID_NEG_SATURATION], @@ -1090,6 +1094,9 @@ static int pidff_find_fields(struct pidff_usage *usage, const u8 *table, else if (table[i] == pidff_set_condition[PID_PARAM_BLOCK_OFFSET]) PIDFF_MISSING_FIELD(PBO, quirks); + else if (table[i] == pidff_set_condition[PID_NEG_COEFFICIENT]) + PIDFF_MISSING_FIELD(NEG_COEFFICIENT, quirks); + else if (strict) { pr_debug("failed to locate %d\n", i); return -1; diff --git a/drivers/hid/usbhid/hid-pidff.h b/drivers/hid/usbhid/hid-pidff.h index f321f675e1318..5bf54e981543b 100644 --- a/drivers/hid/usbhid/hid-pidff.h +++ b/drivers/hid/usbhid/hid-pidff.h @@ -21,6 +21,9 @@ /* Force all periodic effects to be uploaded as SINE */ #define HID_PIDFF_QUIRK_PERIODIC_SINE_ONLY BIT(4) +/* Allow devices with missing negative coefficient in the set condition usage */ +#define HID_PIDFF_QUIRK_MISSING_NEG_COEFFICIENT BIT(5) + #ifdef CONFIG_HID_PID int hid_pidff_init(struct hid_device *hid); int hid_pidff_init_with_quirks(struct hid_device *hid, u32 initial_quirks);