# \[PATCH v2 5/9\] HID: haptic: Postpone GET\_REPORT to init - From: Rong Zhang \ - Date: 2026-11-09 19:50:50 - List: linux-input - Page: https://ratatoskr.run/linux-input/2026/11/17899719 - Thread: https://ratatoskr.run/linux-input/2026/11/17899714/t.md ```text Currently, the driver calls GET_REPORT within the feature_mapping callback. This is not optimal, as the driver works only if manual trigger is also available and the if the device is a touchpad. It makes no sense to initiate device IO if the device is not supported by the driver. Hence, postpone GET_REPORT to hid_haptic_init(), and parse default trigger in parse_auto_trigger_field() where many fields are already parsed there. Signed-off-by: Rong Zhang --- drivers/hid/hid-haptic.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/hid/hid-haptic.c b/drivers/hid/hid-haptic.c index 84985ad61d45..9f2af082d2ea 100644 --- a/drivers/hid/hid-haptic.c +++ b/drivers/hid/hid-haptic.c @@ -22,13 +22,6 @@ void hid_haptic_feature_mapping(struct hid_device *hdev, "HID_HP_AUTOTRIGGER out of range\n"); return; } - - hid_device_io_start(hdev); - hid_hw_request(hdev, field->report, HID_REQ_GET_REPORT); - hid_hw_wait(hdev); - hid_device_io_stop(hdev); - haptic->default_auto_trigger = - field->value[usage->usage_index]; haptic->auto_trigger_report = field->report; } else if ((usage->hid & HID_USAGE_PAGE) == HID_UP_ORDINAL) { usage_hid = usage->hid & HID_USAGE; @@ -146,6 +139,9 @@ static void parse_auto_trigger_field(struct hid_haptic_device *haptic, break; case HID_UP_HAPTIC: switch (field->usage[n].hid) { + case HID_HP_AUTOTRIGGER: + haptic->default_auto_trigger = field->value[n]; + break; case HID_HP_WAVEFORMVENDORID: haptic->vendor_id = field->value[n]; break; @@ -465,6 +461,12 @@ int hid_haptic_init(struct hid_device *hdev, HID_HP_WAVEFORMSTOP & HID_USAGE; mutex_init(&haptic->auto_trigger_mutex); + + hid_device_io_start(hdev); + hid_hw_request(hdev, haptic->auto_trigger_report, HID_REQ_GET_REPORT); + hid_hw_wait(hdev); + hid_device_io_stop(hdev); + for (r = 0; r < haptic->auto_trigger_report->maxfield; r++) parse_auto_trigger_field(haptic, haptic->auto_trigger_report->field[r]); -- 2.55.0 ```