This is a note to let you know that I've just added the patch titled
HID: logitech-hidpp: Don't restart IO, instead defer hid_connect() only
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
hid-logitech-hidpp-don-t-restart-io-instead-defer-hi.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e320737df23de27f8e34d4a963b88d45934b31b3
Author: Hans de Goede <hdegoede@xxxxxxxxxx>
Date: Tue Oct 10 12:20:18 2023 +0200
HID: logitech-hidpp: Don't restart IO, instead defer hid_connect() only
[ Upstream commit 11ca0322a41920df2b462d2e45b0731e47ff475b ]
Restarting IO causes 2 problems:
1. Some devices do not like IO being restarted this was addressed in
commit 498ba2069035 ("HID: logitech-hidpp: Don't restart communication
if not necessary"), but that change has issues of its own and needs to
be reverted.
2. Restarting IO and specifically calling hid_device_io_stop() causes
received packets to be missed, which may cause connect-events to
get missed.
Restarting IO was introduced in commit 91cf9a98ae41 ("HID: logitech-hidpp:
make .probe usbhid capable") to allow to retrieve the device's name and
serial number and store these in hdev->name and hdev->uniq before
connecting any hid subdrivers (hid-input, hidraw) exporting this info
to userspace.
But this does not require restarting IO, this merely requires deferring
calling hid_connect(). Calling hid_hw_start() with a connect-mask of
0 makes it skip calling hid_connect(), so hidpp_probe() can simply call
hid_connect() later without needing to restart IO.
Remove the stop + restart of IO and instead just call hid_connect() later
to avoid the issues caused by restarting IO.
Now that IO is no longer stopped, hid_hw_close() must be called at the end
of probe() to balance the hid_hw_open() done at the beginning probe().
This series has been tested on the following devices:
Logitech Bluetooth Laser Travel Mouse (bluetooth, HID++ 1.0)
Logitech M720 Triathlon (bluetooth, HID++ 4.5)
Logitech M720 Triathlon (unifying, HID++ 4.5)
Logitech K400 Pro (unifying, HID++ 4.1)
Logitech K270 (eQUAD nano Lite, HID++ 2.0)
Logitech M185 (eQUAD nano Lite, HID++ 4.5)
Logitech LX501 keyboard (27 Mhz, HID++ builtin scroll-wheel, HID++ 1.0)
Logitech M-RAZ105 mouse (27 Mhz, HID++ extra mouse buttons, HID++ 1.0)
And by bentiss:
Logitech Touchpad T650 (unifying)
Logitech Touchpad T651 (bluetooth)
Logitech MX Master 3B (BLE)
Logitech G403 (plain USB / Gaming receiver)
Fixes: 498ba2069035 ("HID: logitech-hidpp: Don't restart communication if not necessary")
Suggested-by: Benjamin Tissoires <bentiss@xxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231010102029.111003-2-hdegoede@xxxxxxxxxx
Signed-off-by: Benjamin Tissoires <bentiss@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index a716c6f3bfb58..907f45dfef4c1 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -4155,8 +4155,10 @@ 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 = hid_hw_start(hdev, will_restart ? 0 : connect_mask);
if (ret) {
@@ -4214,19 +4216,14 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
flush_work(&hidpp->work);
if (will_restart) {
- /* Reset the HID node state */
- hid_device_io_stop(hdev);
- hid_hw_close(hdev);
- hid_hw_stop(hdev);
-
if (hidpp->quirks & HIDPP_QUIRK_DELAYED_INIT)
connect_mask &= ~HID_CONNECT_HIDINPUT;
/* Now export the actual inputs and hidraw nodes to the world */
- ret = hid_hw_start(hdev, connect_mask);
+ ret = hid_connect(hdev, connect_mask);
if (ret) {
- hid_err(hdev, "%s:hid_hw_start returned error\n", __func__);
- goto hid_hw_start_fail;
+ hid_err(hdev, "%s:hid_connect returned error %d\n", __func__, ret);
+ goto hid_hw_init_fail;
}
}
@@ -4238,6 +4235,11 @@ 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:
