lkml.org 
[lkml]   [2019]   [Sep]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH v2 2/2] PTP: add support for one-shot output
Date

Hi,

Richard Cochran <richardcochran@gmail.com> writes:
> On Fri, Aug 30, 2019 at 11:00:20AM +0300, Felipe Balbi wrote:
>> >> @@ -177,9 +177,8 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
>> >> err = -EFAULT;
>> >> break;
>> >> }
>> >> - if ((req.perout.flags || req.perout.rsv[0] || req.perout.rsv[1]
>> >> - || req.perout.rsv[2] || req.perout.rsv[3])
>> >> - && cmd == PTP_PEROUT_REQUEST2) {
>> >> + if ((req.perout.rsv[0] || req.perout.rsv[1] || req.perout.rsv[2]
>> >> + || req.perout.rsv[3]) && cmd == PTP_PEROUT_REQUEST2) {
>> >
>> > Please check that the reserved bits of req.perout.flags, namely
>> > ~PTP_PEROUT_ONE_SHOT, are clear.
>>
>> Actually, we should check more. PEROUT_FEATURE_ENABLE is still valid
>> here, right? So are RISING and FALLING edges, no?
>
> No. The ptp_extts_request.flags are indeed defined:
>
> struct ptp_extts_request {
> ...
> unsigned int flags; /* Bit field for PTP_xxx flags. */
> ...
> };
>
> But the ptp_perout_request.flags are reserved:
>
> struct ptp_perout_request {
> ...
> unsigned int flags; /* Reserved for future use. */
> ...
> };

This a bit confusing, really. Specially when the comment right above
those flags states:

/* PTP_xxx bits, for the flags field within the request structures. */

The request "structures" include EXTTS and PEROUT:

struct ptp_clock_request {
enum {
PTP_CLK_REQ_EXTTS,
PTP_CLK_REQ_PEROUT,
PTP_CLK_REQ_PPS,
} type;
union {
struct ptp_extts_request extts;
struct ptp_perout_request perout;
};
};

Seems like we will, at least, make it clear which flags are valid for
which request structures.

> For this ioctl, the test for enable/disable is
> ptp_perout_request.period is zero:
>
> enable = req.perout.period.sec || req.perout.period.nsec;
> err = ops->enable(ops, &req, enable);
>
> The usage pattern here is taken from timer_settime(2).

got it

--
balbi
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2019-09-05 12:04    [W:0.094 / U:0.820 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site