Re: [PATCH 1/2] staging: r8188eu: Use usb_control_msg_recv/send() in usbctrl_vendorreq()

[Fabio M. De Francesco]

On Tuesday, August 24, 2021 2:08:49 AM CEST Phillip Potter wrote:
> On Mon, 23 Aug 2021 at 23:38, Fabio M. De Francesco
> <fmdefrancesco@xxxxxxxxx> wrote:
> >
> > Replace usb_control_msg() with the new usb_control_msg_recv() and
> > usb_control_msg_send() API of USB Core in usbctrl_vendorreq().
> >
> > Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx>
> > ---
> >
> > Thanks to Pavel Skripkin <paskripkin@xxxxxxxxx> for his review of the
> > RFC patch.
> >
> > drivers/staging/r8188eu/hal/usb_ops_linux.c | 25 ++++++++++-----------
> > 1 file changed, 12 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/staging/r8188eu/hal/usb_ops_linux.c b/drivers/staging/r8188eu/hal/usb_ops_linux.c
> > index a93d5cfe4635..6f51660b967a 100644
> > --- a/drivers/staging/r8188eu/hal/usb_ops_linux.c
> > +++ b/drivers/staging/r8188eu/hal/usb_ops_linux.c
> > @@ -15,9 +15,8 @@ static int usbctrl_vendorreq(struct intf_hdl *pintfhdl, u16 value, void *pdata,
> >         struct adapter  *adapt = pintfhdl->padapter;
> >         struct dvobj_priv  *dvobjpriv = adapter_to_dvobj(adapt);
> >         struct usb_device *udev = dvobjpriv->pusbdev;
> > -       unsigned int pipe;
> > +       u8 pipe;
> >         int status = 0;
> > -       u8 reqtype;
> >         u8 *pIo_buf;
> >         int vendorreq_times = 0;
> >
> > @@ -44,22 +43,22 @@ static int usbctrl_vendorreq(struct intf_hdl *pintfhdl, u16 value, void *pdata,
> >         }
> >
> >         while (++vendorreq_times <= MAX_USBCTRL_VENDORREQ_TIMES) {
> > -               memset(pIo_buf, 0, len);
> > -
> >                 if (requesttype == 0x01) {
> > -                       pipe = usb_rcvctrlpipe(udev, 0);/* read_in */
> > -                       reqtype =  REALTEK_USB_VENQT_READ;
> > +                       status = usb_control_msg_recv(udev, pipe, REALTEK_USB_VENQT_CMD_REQ,
> > +                                                     REALTEK_USB_VENQT_READ, value,
> > +                                                     REALTEK_USB_VENQT_CMD_IDX,
> > +                                                     pIo_buf, len, RTW_USB_CONTROL_MSG_TIMEOUT,
> > +                                                     GFP_KERNEL);
> >                 } else {
> > -                       pipe = usb_sndctrlpipe(udev, 0);/* write_out */
> > -                       reqtype =  REALTEK_USB_VENQT_WRITE;
> >                         memcpy(pIo_buf, pdata, len);
> > +                       status = usb_control_msg_send(udev, pipe, REALTEK_USB_VENQT_CMD_REQ,
> > +                                                     REALTEK_USB_VENQT_WRITE, value,
> > +                                                     REALTEK_USB_VENQT_CMD_IDX,
> > +                                                     pIo_buf, len, RTW_USB_CONTROL_MSG_TIMEOUT,
> > +                                                     GFP_KERNEL);
> >                 }
> >
> > -               status = usb_control_msg(udev, pipe, REALTEK_USB_VENQT_CMD_REQ,
> > -                                        reqtype, value, REALTEK_USB_VENQT_CMD_IDX,
> > -                                        pIo_buf, len, RTW_USB_CONTROL_MSG_TIMEOUT);
> > -
> > -               if (status == len) {   /*  Success this control transfer. */
> > +               if (!status) {   /*  Success this control transfer. */
> >                         rtw_reset_continual_urb_error(dvobjpriv);
> >                         if (requesttype == 0x01)
> >                                 memcpy(pdata, pIo_buf,  len);
> > --
> > 2.32.0
> >
> 
> Dear Fabio,
> 
> Thanks for the patch. Sorry, but for some reason with my N10-Nano I
> can't get a connection at all with this patch applied - it just won't
> associate with my network. Interface shows up and no OOPS in log, but
> just disassociates/no IP address/interface down etc. so perhaps
> semantics differ slightly here somehow? Tried two separate
> rollbacks/builds/runs just to make sure I wasn't losing my mind :-)
> 
> Regards,
> Phil
> 
Dear Philip,

Thanks for testing. As I wrote in my RFC, I strongly suspected that I was
not able to correctly understand the semantics of the new API. I'll try to
read the code anew and try to understand what is wrong here.

However, I also think that I won't be able to figure it out. Maybe that I 
have to wait for Greg to give me some hint about what are the errors in
using usb_control_msg_send/recv() the way I did.

Anyway, thanks a lot for the time you spent testing.

Regards,

Fabio