6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx> [ Upstream commit 94d05394254401e503867c16aff561d3e687dfdc ] Serdev recv_buf() callback is supposed to return the amount of bytes consumed, therefore an int in between 0 and count. Do not return a negative number in case of issue, just print an error and return count. Before this change, in case of error, the returned negative number was internally converted to 0 in ttyport_receive_buf, now when the receive buffer is corrupted we return the size of the whole received data (`count`). This should allow for better recovery in case receiver/transmitter get out of sync if some data is lost. This fixes a WARN in ttyport_receive_buf(). Bluetooth: hci0: Frame reassembly failed (-84) ------------[ cut here ]------------ serial serial0: receive_buf returns -84 (count = 6) WARNING: CPU: 0 PID: 37 at drivers/tty/serdev/serdev-ttyport.c:37 ttyport_receive_buf+0xd8/0xf8 Modules linked in: mwifiex_sdio(+) ... CPU: 0 PID: 37 Comm: kworker/u4:2 Not tainted 6.7.0-rc2-00147-gf1a09972a45a #1 Hardware name: Toradex Verdin AM62 WB on Verdin Development Board (DT) Workqueue: events_unbound flush_to_ldisc pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : ttyport_receive_buf+0xd8/0xf8 lr : ttyport_receive_buf+0xd8/0xf8 ... Call trace: ttyport_receive_buf+0xd8/0xf8 flush_to_ldisc+0xbc/0x1a4 process_scheduled_works+0x16c/0x28c Closes: https://lore.kernel.org/all/ZWEIhcUXfutb5SY6@xxxxxxxxxxxxxxxxxxxxxxxxxxxx/ Fixes: 689ca16e5232 ("Bluetooth: NXP: Add protocol support for NXP Bluetooth chipsets") Signed-off-by: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/bluetooth/btnxpuart.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c index b7e66b7ac570..951fe3014a3f 100644 --- a/drivers/bluetooth/btnxpuart.c +++ b/drivers/bluetooth/btnxpuart.c @@ -1276,11 +1276,10 @@ static int btnxpuart_receive_buf(struct serdev_device *serdev, const u8 *data, if (IS_ERR(nxpdev->rx_skb)) { int err = PTR_ERR(nxpdev->rx_skb); /* Safe to ignore out-of-sync bootloader signatures */ - if (is_fw_downloading(nxpdev)) - return count; - bt_dev_err(nxpdev->hdev, "Frame reassembly failed (%d)", err); + if (!is_fw_downloading(nxpdev)) + bt_dev_err(nxpdev->hdev, "Frame reassembly failed (%d)", err); nxpdev->rx_skb = NULL; - return err; + return count; } if (!is_fw_downloading(nxpdev)) nxpdev->hdev->stat.byte_rx += count; -- 2.43.0