Re: [PATCH v4] Bluetooth: hci_qca: wcn3990: Drop baudrate change vendor event

[Marcel Holtmann]

Hi Matthias,

> Firmware download to the WCN3990 often fails with a 'TLV response size
> mismatch' error:
> 
> [  133.064659] Bluetooth: hci0: setting up wcn3990
> [  133.489150] Bluetooth: hci0: QCA controller version 0x02140201
> [  133.495245] Bluetooth: hci0: QCA Downloading qca/crbtfw21.tlv
> [  133.507214] Bluetooth: hci0: QCA TLV response size mismatch
> [  133.513265] Bluetooth: hci0: QCA Failed to download patch (-84)
> 
> This is caused by a vendor event that corresponds to an earlier command
> to change the baudrate. The event is not processed in the context of the
> baudrate change and is later interpreted as response to the firmware
> download command (which is also a vendor command), but the driver detects
> that the event doesn't have the expected amount of associated data.
> 
> More details:
> 
> For the WCN3990 the vendor command for a baudrate change isn't sent as
> synchronous HCI command, because the controller sends the corresponding
> vendor event with the new baudrate. The event is received and decoded
> after the baudrate change of the host port.
> 
> Identify the 'unused' event when it is received and don't add it to
> the queue of RX frames.
> 
> Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> ---
> Changes in v4:
> - limit the fix to WCN3990 instead of applying it to all WCN399x.
>  Harish Bandi <c-hbandi@xxxxxxxxxxxxxx> reported frame reassembly
>  errors with WCN3998 and v3. At this point it is unknown in how far
>  WCN3998 behaves different from WCN3990, we can revisit
>  it later if it turns that it has the same problem.
> 
> Changes in v3:
> - rebased on latest bluetooth-next/master
> - removed barrier calls again, bit routines include barriers
> 
> Changes in v2:
> - make QCA_DROP_VENDOR_EVENT an enum value and don't use BIT()
> - free skb in qca_recv_event()
> - add barriers to ensure qca_recv_event() sees updated flags
> - return -ETIMEDOUT instead of -EPROTO if the vendor event isn't
>  received in time
> ---
> drivers/bluetooth/hci_qca.c | 55 ++++++++++++++++++++++++++++++++++++-
> 1 file changed, 54 insertions(+), 1 deletion(-)

patch has been applied to bluetooth-next tree.

Regards

Marcel