On Tue, Aug 20, 2019 at 04:48:39PM +0300, Vladimir Oltean wrote:
> On Tue, 20 Aug 2019 at 15:55, Mark Brown wrote:
> > On Fri, Aug 16, 2019 at 05:05:53PM +0300, Vladimir Oltean wrote:
> > > Maybe the SPI master driver should just report what sort of
> > > snapshotting capability it can offer, ran
Hi Mark,
On Tue, 20 Aug 2019 at 15:55, Mark Brown wrote:
>
> On Fri, Aug 16, 2019 at 05:05:53PM +0300, Vladimir Oltean wrote:
>
> > I'm not sure how to respond to this, because I don't know anything
> > about the timing of DMA transfers.
> > Maybe snapshotting DMA transfers the same way is not po
On Fri, Aug 16, 2019 at 05:05:53PM +0300, Vladimir Oltean wrote:
> I'm not sure how to respond to this, because I don't know anything
> about the timing of DMA transfers.
> Maybe snapshotting DMA transfers the same way is not possible (if at
> all). Maybe they are not exactly adequate for this sor
> MDIO bus controllers are in a similar situation (with Hubert's patch)
> but at least there the frame size is fixed and I haven't heard of an
> MDIO controller to use DMA.
Linux does not have any DMA driver MDIO busses, as far as i know. It
does not make sense, since you are only transferring 16b
On Fri, 16 Aug 2019 at 15:58, Mark Brown wrote:
>
> On Fri, Aug 16, 2019 at 03:35:30PM +0300, Vladimir Oltean wrote:
> > On Fri, 16 Aug 2019 at 15:18, Mark Brown wrote:
> > > On Fri, Aug 16, 2019 at 03:44:41AM +0300, Vladimir Oltean wrote:
>
> > > > @@ -842,6 +843,9 @@ struct spi_transfer {
> > >
On Fri, Aug 16, 2019 at 03:35:30PM +0300, Vladimir Oltean wrote:
> On Fri, 16 Aug 2019 at 15:18, Mark Brown wrote:
> > On Fri, Aug 16, 2019 at 03:44:41AM +0300, Vladimir Oltean wrote:
> > > @@ -842,6 +843,9 @@ struct spi_transfer {
> > >
> > > u32 effective_speed_hz;
> > >
> > >
Hi Mark,
On Fri, 16 Aug 2019 at 15:18, Mark Brown wrote:
>
> On Fri, Aug 16, 2019 at 03:44:41AM +0300, Vladimir Oltean wrote:
>
> > @@ -842,6 +843,9 @@ struct spi_transfer {
> >
> > u32 effective_speed_hz;
> >
> > + struct ptp_system_timestamp *ptp_sts;
> > + unsigned in
On Fri, Aug 16, 2019 at 03:44:41AM +0300, Vladimir Oltean wrote:
> @@ -842,6 +843,9 @@ struct spi_transfer {
>
> u32 effective_speed_hz;
>
> + struct ptp_system_timestamp *ptp_sts;
> + unsigned intptp_sts_word_offset;
> +
You've not documented these fields at all
SPI is one of the interfaces used to access devices which have a POSIX
clock driver (real time clocks, 1588 timers etc).
Since there are lots of sources of timing jitter when retrieving the
time from such a device (controller delays, locking contention etc),
introduce a PTP system timestamp struct
