Patch "Bluetooth: btmtkuart: fix recv_buf() return value" has been added to the 4.19-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    Bluetooth: btmtkuart: fix recv_buf() return value

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     bluetooth-btmtkuart-fix-recv_buf-return-value.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 4694478806b34e2d968faab5068b1392e6443605
Author: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx>
Date:   Mon Dec 11 17:40:19 2023 +0100

    Bluetooth: btmtkuart: fix recv_buf() return value
    
    [ Upstream commit 64057f051f20c2a2184b9db7f8037d928d68a4f4 ]
    
    Serdev recv_buf() callback is supposed to return the amount of bytes
    consumed, therefore an int in between 0 and count.
    
    Do not return negative number in case of issue, just print an error and
    return count. This fixes a WARN in ttyport_receive_buf().
    
    Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@xxxxxxxxxx/
    Fixes: 7237c4c9ec92 ("Bluetooth: mediatek: Add protocol support for MediaTek serial devices")
    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>

diff --git a/drivers/bluetooth/btmtkuart.c b/drivers/bluetooth/btmtkuart.c
index 19eecf198321..cda13194b131 100644
--- a/drivers/bluetooth/btmtkuart.c
+++ b/drivers/bluetooth/btmtkuart.c
@@ -317,7 +317,7 @@ mtk_stp_split(struct btmtkuart_dev *bdev, const unsigned char *data, int count,
 	return data;
 }
 
-static int btmtkuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
+static void btmtkuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
 {
 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
 	const unsigned char *p_left = data, *p_h4;
@@ -356,25 +356,20 @@ static int btmtkuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
 			bt_dev_err(bdev->hdev,
 				   "Frame reassembly failed (%d)", err);
 			bdev->rx_skb = NULL;
-			return err;
+			return;
 		}
 
 		sz_left -= sz_h4;
 		p_left += sz_h4;
 	}
-
-	return 0;
 }
 
 static int btmtkuart_receive_buf(struct serdev_device *serdev, const u8 *data,
 				 size_t count)
 {
 	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
-	int err;
 
-	err = btmtkuart_recv(bdev->hdev, data, count);
-	if (err < 0)
-		return err;
+	btmtkuart_recv(bdev->hdev, data, count);
 
 	bdev->hdev->stat.byte_rx += count;