On Mon, May 24, 2021 at 01:09:20PM +0200, Johan Hovold wrote:
> The direction of the pipe argument must match the request-type direction
> bit or control requests may fail depending on the host-controller-driver
> implementation.
>
> Control transfers without a data stage are treated as OUT requests by
> the USB stack and should be using usb_sndctrlpipe(). Failing to do so
> will now trigger a warning.
>
> Fix the zero-length i2c-read request used for type detection by
> attempting to read a single byte instead.
>
> Reported-by: syzbot+faf11bbadc5a372564da@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: d0f232e823af ("[media] rtl28xxu: add heuristic to detect chip type")
> Cc: stable@xxxxxxxxxxxxxxx # 4.0
> Cc: Antti Palosaari <crope@xxxxxx>
> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> ---
> drivers/media/usb/dvb-usb-v2/rtl28xxu.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
> index 97ed17a141bb..2c04ed8af0e4 100644
> --- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
> +++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
> @@ -612,8 +612,9 @@ static int rtl28xxu_read_config(struct dvb_usb_device *d)
> static int rtl28xxu_identify_state(struct dvb_usb_device *d, const char **name)
> {
> struct rtl28xxu_dev *dev = d_to_priv(d);
> + u8 buf[1];
> int ret;
> - struct rtl28xxu_req req_demod_i2c = {0x0020, CMD_I2C_DA_RD, 0, NULL};
> + struct rtl28xxu_req req_demod_i2c = {0x0020, CMD_I2C_DA_RD, 1, buf};
>
> dev_dbg(&d->intf->dev, "\n");
As reported here
https://lore.kernel.org/r/YLSVsrhMZ2oOL1vM@xxxxxxxxxxxxxxxxxxxx
this patch is causing the chip type to no longer be detected correctly,
so please drop this one for now until this has been resolved.
Johan
