Hi Marcel,
Thank you for your patch. This change looks good to me.
I think the scenario you are testing/resolving is:
1) Load btnxpuart.ko first (which "may" load BT-only FW if chip is powered on)
2) Power cycle or power on chip
3) Load WLAN driver with combo FW
Right?
Thanks,
Neeraj
> From: Marcel Ziswiler <marcel@xxxxxxxxxxxx>
> Sent: Wednesday, October 18, 2023 8:26 PM
> To: linux-bluetooth@xxxxxxxxxxxxxxx
> Cc: Sherry Sun <sherry.sun@xxxxxxx>; Johan Hedberg
> <johan.hedberg@xxxxxxxxx>; Luiz Augusto von Dentz
> <luiz.dentz@xxxxxxxxx>; Neeraj sanjay kale <neeraj.sanjaykale@xxxxxxx>;
> linux-kernel@xxxxxxxxxxxxxxx; Marcel Holtmann <marcel@xxxxxxxxxxxx>;
> Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>; Amitkumar Karwar
> <amitkumar.karwar@xxxxxxx>; Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
> Subject: [PATCH v1 2/2] Bluetooth: btnxpuart: Fix nxp_setup
>
> From: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
>
> Unfortunately, nxp_setup() may inadvertently assume that the firmware is
> already running while the module is not even powered yet.
> Fix this by waiting up to 10 seconds for the CTS to go up as the combo
> firmware might be loaded by the Wi-Fi driver over SDIO (mwifiex_sdio).
>
> Fixes: 689ca16e5232 ("Bluetooth: NXP: Add protocol support for NXP
> Bluetooth chipsets")
>
> Signed-off-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
>
> ---
> This is what may happen without this fix:
> [ 284.588177] Bluetooth: hci0: Opcode 0x0c03 failed: -110 [ 286.636167]
> Bluetooth: hci0: Setting wake-up method failed (-110) Unfortunately, even
> re-loading the btnxpuart kernel module would not recover from this
> condition.
>
> drivers/bluetooth/btnxpuart.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
> index 9cb7529eef09..4b83a0aa3459 100644
> --- a/drivers/bluetooth/btnxpuart.c
> +++ b/drivers/bluetooth/btnxpuart.c
> @@ -1021,6 +1021,16 @@ static int nxp_setup(struct hci_dev *hdev)
> if (err < 0)
> return err;
> } else {
> + /* The combo firmware might be loaded by the Wi-Fi driver over
> SDIO (mwifiex_sdio).
> + * We wait up to 10s for the CTS to go up. Afterwards, we know that
> the firmware is
> + * really ready.
> + */
> + err = serdev_device_wait_for_cts(nxpdev->serdev, true, 10000);
> + if (err) {
> + bt_dev_err(nxpdev->hdev, "Wait for CTS failed with %d", err);
> + return err;
> + }
> +
> bt_dev_dbg(hdev, "FW already running.");
> clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
> }
> --
> 2.36.1
