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Re: [PATCH v4 1/5] Implement an ioctl to support the USMTMC-USB488 READ_STATUS_BYTE operation.

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  Re: [PATCH v4 1/5] Implement an ioctl to support the USMTMC-USB488  READ_STATUS_BYTE operation. Dave Penkler <dpenkler@gmail.com> - 2015-11-18 09:20 +0100

#1271913 — Re: [PATCH v4 1/5] Implement an ioctl to support the USMTMC-USB488 READ_STATUS_BYTE operation.

Hi Andy,
On Sun, Nov 15, 2015 at 10:04:10PM +0200, Andy Shevchenko wrote:
> On Sun, Nov 15, 2015 at 8:39 PM, Dave Penkler <dpenkler@gmail.com> wrote:

snip

> > +
> 
> Redundant empty line.
> 

ok

> 
> > +               data->iin_bTag = 2;
> 
> Hmm??? Why 2?
> A-ha, below I found a comment. Something might be good to have here as well.
> 

Added comment

> > +
> 
> Redundant empty line.
> 

ok

> > +
> > +               if (data->iin_buffer[0] & 0x80) {
> > +                       /* check for valid STB notification */
> > +                       if ((data->iin_buffer[0] & 0x7f) > 1) {
> 
> It's the same as
>      if (data->iin_buffer[0] & 0x7e) {
> 

Yes but when reading the spec and the code it is more obvious that here
we are testing for the value in bits D6..D0 to be a valid iin_bTag return. 
(See Table 7 in the USBTMC-USB488 spec.)

> > +               dev_dbg(&data->intf->dev,
> > +                       "%s - urb terminated, status: %d\n",
> 
> I heard that dynamic debug adds function name.
> 
> > +                       __func__, status);

I checked in device.h and could not find any trace of it. I'm on 4.4.0-rc1.

> > +static void usbtmc_free_int(struct usbtmc_device_data *data)
> > +{
> > +       if (data->iin_ep_present) {
> > +               if (data->iin_urb) {
> 
> Why not
> 
> if (!data->iin_ep_present || !data->iin_urb)
>   return;
> 
> ?
> 

OK

Thanks,
-Dave
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