Re: [PATCH AUTOSEL 5.4 133/350] Bluetooth: hci_bcm: Fix RTS handling during startup

Stefan Wahren
2019-12-16T18:46:38Z

Am 16.12.19 um 14:27 schrieb Greg KH:
> On Mon, Dec 16, 2019 at 02:15:12PM +0100, Ondřej Jirman wrote:
>> Hi,
>>
>> On Tue, Dec 10, 2019 at 04:03:58PM -0500, Sasha Levin wrote:
>>> From: Stefan Wahren <wahrenst@gmx.net>
>>>
>>> [ Upstream commit 3347a80965b38f096b1d6f995c00c9c9e53d4b8b ]
>>>
>>> The RPi 4 uses the hardware handshake lines for CYW43455, but the chip
>>> doesn't react to HCI requests during DT probe. The reason is the inproper
>>> handling of the RTS line during startup. According to the startup
>>> signaling sequence in the CYW43455 datasheet, the hosts RTS line must
>>> be driven after BT_REG_ON and BT_HOST_WAKE.
>>>
>>> Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
>>> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
>>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>>> ---
>>> drivers/bluetooth/hci_bcm.c | 2 ++
>>> 1 file changed, 2 insertions(+)
>>>
>>> diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
>>> index 7646636f2d183..0f73f6a686cb7 100644
>>> --- a/drivers/bluetooth/hci_bcm.c
>>> +++ b/drivers/bluetooth/hci_bcm.c
>>> @@ -445,9 +445,11 @@ static int bcm_open(struct hci_uart *hu)
>>>
>>> out:
>>> if (bcm->dev) {
>>> + hci_uart_set_flow_control(hu, true);
>>> hu->init_speed = bcm->dev->init_speed;
>>> hu->oper_speed = bcm->dev->oper_speed;
>>> err = bcm_gpio_set_power(bcm->dev, true);
>>> + hci_uart_set_flow_control(hu, false);
>>> if (err)
>>> goto err_unset_hu;
>>> }
>> This causes bluetooth breakage (degraded bluetooth performance, due to failure to
>> switch to higher baudrate) for Orange Pi 3 board:
>>
>> [ 3.839134] Bluetooth: hci0: command 0xfc18 tx timeout
>> [ 11.999136] Bluetooth: hci0: BCM: failed to write update baudrate (-110)
>> [ 12.004613] Bluetooth: hci0: Failed to set baudrate
>> [ 12.123187] Bluetooth: hci0: BCM: chip id 130
>> [ 12.128398] Bluetooth: hci0: BCM: features 0x0f
>> [ 12.154686] Bluetooth: hci0: BCM4345C5
>> [ 12.157165] Bluetooth: hci0: BCM4345C5 (003.006.006) build 0000
>> [ 15.343684] Bluetooth: hci0: BCM4345C5 (003.006.006) build 0038
>>
>> I suggest not pushing this to stable.
> Is it being fixed in Linus's tree?

No, because this mail was the first bug report.

But i agree with Ondřej to not push it into stable.

Stefan

>
> thanks,
>
> greg k-h