Re: [PATCH] RFC: Bluetooth: missed cpu_to_le16 conversion in hci_init4_req

From: Simon Horman
Date: Thu Oct 17 2019 - 08:43:06 EST


On Wed, Oct 16, 2019 at 08:42:48PM +0200, Marcel Holtmann wrote:
> Hi Simon,
>
> >> It looks like in hci_init4_req() the request is being
> >> initialised from cpu-endian data but the packet is specified
> >> to be little-endian. This causes an warning from sparse due
> >> to __le16 to u16 conversion.
> >>
> >> Fix this by using cpu_to_le16() on the two fields in the packet.
> >>
> >> net/bluetooth/hci_core.c:845:27: warning: incorrect type in assignment (different base types)
> >> net/bluetooth/hci_core.c:845:27: expected restricted __le16 [usertype] tx_len
> >> net/bluetooth/hci_core.c:845:27: got unsigned short [usertype] le_max_tx_len
> >> net/bluetooth/hci_core.c:846:28: warning: incorrect type in assignment (different base types)
> >> net/bluetooth/hci_core.c:846:28: expected restricted __le16 [usertype] tx_time
> >> net/bluetooth/hci_core.c:846:28: got unsigned short [usertype] le_max_tx_time
> >>
> >> Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx>
> >> ---
> >> Cc: Marcel Holtmann <marcel@xxxxxxxxxxxx>
> >> Cc: Johan Hedberg <johan.hedberg@xxxxxxxxx>
> >> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> >> Cc: linux-bluetooth@xxxxxxxxxxxxxxx
> >> Cc: netdev@xxxxxxxxxxxxxxx
> >> Cc: linux-kernel@xxxxxxxxxxxxxxx
> >> ---
> >> net/bluetooth/hci_core.c | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> >> index 04bc79359a17..b2559d4bed81 100644
> >> --- a/net/bluetooth/hci_core.c
> >> +++ b/net/bluetooth/hci_core.c
> >> @@ -842,8 +842,8 @@ static int hci_init4_req(struct hci_request *req, unsigned long opt)
> >> if (hdev->le_features[0] & HCI_LE_DATA_LEN_EXT) {
> >> struct hci_cp_le_write_def_data_len cp;
> >>
> >> - cp.tx_len = hdev->le_max_tx_len;
> >> - cp.tx_time = hdev->le_max_tx_time;
> >> + cp.tx_len = cpu_to_le16(hdev->le_max_tx_len);
> >> + cp.tx_time = cpu_to_le16(hdev->le_max_tx_time);
> >
> > I would suggest that the naming of the le_ fields of struct hci_dev
> > implies that the values stored in those fields should be little endian
> > (but those that are more than bone byte wide are not).
>
> the le_ stands for Low Energy and not for Little Endian.

Thanks, in that case I have no objections.