Hi Paul,
On Tue, Sep 10, 2024 at 3:31 AM Paul Menzel <pmenzel@xxxxxxxxxxxxx> wrote:
>
> Dear Luiz,
>
>
> Thank you for your patch.
>
> Am 09.09.24 um 22:51 schrieb Luiz Augusto von Dentz:
> > From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
> >
> > 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
>
> (*interrupt* would fit on the line above.)
>
> > 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.
>
> Do you have a benchmark script, that can be run?
It is a **may** not a might and not the main objective of the change.
> > Fixes: 5e23b923da03 ("[Bluetooth] Add generic driver for Bluetooth USB devices")
> > Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
> > ---
> > drivers/bluetooth/btusb.c | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> > index 36a869a57910..83df387aea92 100644
> > --- a/drivers/bluetooth/btusb.c
> > +++ b/drivers/bluetooth/btusb.c
> > @@ -1341,7 +1341,10 @@ 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) {
>
>
> Kind regards,
>
> Paul
>
> Kind regards,
>
> Paul
--
Luiz Augusto von Dentz
