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

["Fabio M. De Francesco" <fmdefrancesco@gmail.com>]

On Tuesday, August 24, 2021 2:31:11 AM CEST Fabio M. De Francesco wrote:
> 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@gmail.com> 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@linuxfoundation.org>
> > > Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
> > > ---
> > >
> > > Thanks to Pavel Skripkin <paskripkin@gmail.com> 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
> 
Dear Philip,

I think that I've inadvertently switched the order by which usb_control_msg_send()
and memcpy() are called. I'm very sorry for not doing my tests, but (as I had said 
before) at the moment I don't have my device with me.

I'm about to send a v2 series.

Thanks very much for testing on my behalf.

Regards,

Fabio