On Fri, Oct 19, 2018 at 11:51:37AM +0200, Miroslav Lichvar wrote: > A solution to this would be a new driver function that wraps the > latching register read with readings of the system clock and return > three timestamps instead of one. For example: > > ktime_get_real_ts64(&sys_ts1); > IXGBE_READ_REG(hw, IXGBE_SYSTIMR); > ktime_get_real_ts64(&sys_ts2); > phc_ts.tv_nsec = IXGBE_READ_REG(hw, IXGBE_SYSTIML); > phc_ts.tv_sec = IXGBE_READ_REG(hw, IXGBE_SYSTIMH);
Makes sense... > The extra timestamp doesn't fit the API of the PTP_SYS_OFFSET ioctl, > so it would need to shift the timestamp it returns by the missing > intervals (assuming the frequency offset between the PHC and system > clock is small), or a new ioctl could be introduced that would return > all timestamps in an array looking like this: > > [sys, phc, sys, sys, phc, sys, ...] How about a new ioctl with number of trials as input and single offset as output? Then it would be up to the driver to implement the device-specific loop. Thanks, Richard
