While restarting IO incoming packets get disabled by calling hid_device_io_stop() and they do not get re-enabled again until the hid-core enables the when probe() is done. This leaves a window where connect events may get lost, causing hidpp to not be aware that a device has (dis)connected. To fix this fully restart IO using the new hidpp_connect_and_start() helper and move the connected check to after restarting IO. This requires calling hid_hw_close() at the end of probe() to balance the open() now done on restart. Reported-by: Benjamin Tissoires <bentiss@xxxxxxxxxx> Closes: https://lore.kernel.org/linux-input/zjiang3fdy4o7r3daupwpnx6zesmeeerldpx5fno2adzialpre@cdp7tq4araww/ Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- drivers/hid/hid-logitech-hidpp.c | 33 ++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c index 45b371e7b9ee..ff834f905eda 100644 --- a/drivers/hid/hid-logitech-hidpp.c +++ b/drivers/hid/hid-logitech-hidpp.c @@ -4482,8 +4482,10 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id) hdev->name); /* - * Plain USB connections need to actually call start and open - * on the transport driver to allow incoming data. + * First call hid_hw_start(hdev, 0) to allow IO without connecting any + * hid subdrivers (hid-input, hidraw). This allows retrieving the dev's + * name and serial number and store these in hdev->name and hdev->uniq, + * before the hid-input and hidraw drivers expose these to userspace. */ ret = hidpp_connect_and_start(hidpp, 0); if (ret) @@ -4495,18 +4497,12 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id) else hidpp_non_unifying_init(hidpp); - connected = hidpp_root_get_protocol_version(hidpp) == 0; - atomic_set(&hidpp->connected, connected); - if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920) { ret = g920_get_config(hidpp, &data); if (ret) goto hid_hw_init_fail; } - schedule_work(&hidpp->work); - flush_work(&hidpp->work); - /* Reset the HID node state */ hid_device_io_stop(hdev); hid_hw_close(hdev); @@ -4516,11 +4512,19 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id) connect_mask &= ~HID_CONNECT_HIDINPUT; /* Now export the actual inputs and hidraw nodes to the world */ - ret = hid_hw_start(hdev, connect_mask); - if (ret) { - hid_err(hdev, "%s:hid_hw_start returned error\n", __func__); + ret = hidpp_connect_and_start(hidpp, connect_mask); + if (ret) goto hid_hw_start_fail; - } + + /* + * Now that incoming packets are enabled and will not be disabled + * again (which may cause missing packets) check the connected state + * of the device. + */ + connected = hidpp_root_get_protocol_version(hidpp) == 0; + atomic_set(&hidpp->connected, connected); + schedule_work(&hidpp->work); + flush_work(&hidpp->work); if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920) { ret = hidpp_ff_init(hidpp, &data); @@ -4530,6 +4534,11 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id) ret); } + /* + * This relies on logi_dj_ll_close() being a no-op so that DJ connection + * events will still be received. + */ + hid_hw_close(hdev); return ret; hid_hw_init_fail: -- 2.41.0
