This is a note to let you know that I've just added the patch titled Bluetooth: btusb: Fix not handling ZPL/short-transfer to the 6.6-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: bluetooth-btusb-fix-not-handling-zpl-short-transfer.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c8067d098a83433dd77692cb2de6009e93d812a2 Author: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> Date: Mon Sep 9 16:51:52 2024 -0400 Bluetooth: btusb: Fix not handling ZPL/short-transfer [ Upstream commit 7b05933340f4490ef5b09e84d644d12484b05fdf ] Requesting transfers of the exact same size of wMaxPacketSize may result in ZPL/short-transfer since the USB stack cannot handle it as we are limiting the buffer size to be the same as wMaxPacketSize. Also, in terms of throughput this change has the same effect to interrupt endpoint as 290ba200815f "Bluetooth: Improve USB driver throughput by increasing the frame size" had for the bulk endpoint, so users of the advertisement bearer (e.g. BT Mesh) may benefit from this change. Fixes: 5e23b923da03 ("[Bluetooth] Add generic driver for Bluetooth USB devices") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> Tested-by: Kiran K <kiran.k@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c index c495fceda20a2..0a58106207b0c 100644 --- a/drivers/bluetooth/btusb.c +++ b/drivers/bluetooth/btusb.c @@ -1352,7 +1352,10 @@ static int btusb_submit_intr_urb(struct hci_dev *hdev, gfp_t mem_flags) if (!urb) return -ENOMEM; - size = le16_to_cpu(data->intr_ep->wMaxPacketSize); + /* Use maximum HCI Event size so the USB stack handles + * ZPL/short-transfer automatically. + */ + size = HCI_MAX_EVENT_SIZE; buf = kmalloc(size, mem_flags); if (!buf) {