Re: [PATCH v5 1/5] Implement an ioctl to support the USMTMC-USB488 READ_STATUS_BYTE operation.

Andy Shevchenko
2015-11-28T19:18:16Z

On Sat, Nov 28, 2015 at 7:41 PM, Dave Penkler <dpenkler@gmail.com> wrote:
> On Sat, Nov 28, 2015 at 04:57:47PM +0200, Andy Shevchenko wrote:
>> On Sat, Nov 28, 2015 at 1:55 PM, Dave Penkler <dpenkler@gmail.com> wrote:
>> > On Wed, Nov 25, 2015 at 10:38:39PM +0200, Andy Shevchenko wrote:
>> >> On Wed, Nov 25, 2015 at 11:18 AM, Dave Penkler <dpenkler@gmail.com> wrote:
>> >> > On Sun, Nov 22, 2015 at 12:32:41PM +0200, Andy Shevchenko wrote:
>> >> >> On Sun, Nov 22, 2015 at 11:19 AM, Dave Penkler <dpenkler@gmail.com> wrote:
>> >> >> > On Wed, Nov 18, 2015 at 11:55:27AM +0200, Andy Shevchenko wrote:
>> >> >> >> On Wed, Nov 18, 2015 at 10:37 AM, Dave Penkler <dpenkler@gmail.com> wrote:
>>
>> Thank you for an update!
>>
>> >> >> >> > + switch (status) {
>> >> >> >> > + case 0: /* SUCCESS */
>> >> >> >> > + if (data->iin_buffer[0] & 0x80) {
>> >> >> >> > + /* check for valid STB notification */
>> >> >> >> > + if ((data->iin_buffer[0] & 0x7f) > 1) {
>>
>> How can I miss that there are two conditionals in a sequence and
>> moreover for the same data?!
>
> Sorry, my fault, it is the combination of patch 1 and 2
>
>> That might explain the optimization done by compiler.
>>
>> So, could it be transformed to simple one condition
>> if (data->iin_buffer[0] > 0x81 /* 129 */) {
>> ?
>
> OK so now for patch 1 and 2 we have:
>
> switch (status) {
> case 0: /* SUCCESS */
> /* PATCH 1 check for valid STB notification */
> if (data->iin_buffer[0] > 0x81) {
> data->bNotify1 = data->iin_buffer[0];
> data->bNotify2 = data->iin_buffer[1];
> atomic_set(&data->iin_data_valid, 1);
> wake_up_interruptible(&data->waitq);
> goto exit;
> }
> /* PATCH 2 check for SRQ notification */
> if (data->iin_buffer[0] == 0x81) {
> if (data->fasync)
> kill_fasync(&data->fasync,
> SIGIO, POLL_IN);
>
> atomic_set(&data->srq_asserted, 1);
> wake_up_interruptible(&data->waitq);
> goto exit;
> }
>
>
> I'll push a new set if you are OK with this.

Yes, fine by me, thanks for patience.

--
With Best Regards,
Andy Shevchenko