Hi Richard, thank you for your comments.
Am Di., 30. Juli 2019 um 18:00 Uhr schrieb Richard Cochran <[email protected]>: [...] > > -/* Raw timestamps are in units of 8-ns clock periods. */ > > -#define CC_SHIFT 28 > > -#define CC_MULT (8 << CC_SHIFT) > > -#define CC_MULT_NUM (1 << 9) > > -#define CC_MULT_DEM 15625ULL > > +/* The adjfine API clamps ppb between [-32,768,000, 32,768,000], and > > That is not true. > > > + * therefore scaled_ppm between [-2,147,483,648, 2,147,483,647]. > > + * Set the maximum supported ppb to a round value smaller than the maximum. > > + * > > + * Percentually speaking, this is a +/- 0.032x adjustment of the > > + * free-running counter (0.968x to 1.032x). > > + */ > > +#define MV88E6XXX_MAX_ADJ_PPB 32000000 > > I had set an arbitrary limit of 1000 ppm. I can't really see any > point in raising the limit. > > > +/* Family MV88E6250: > > + * Raw timestamps are in units of 10-ns clock periods. > > + * > > + * clkadj = scaled_ppm * 10*2^28 / (10^6 * 2^16) > > + * simplifies to > > + * clkadj = scaled_ppm * 2^7 / 5^5 > > + */ > > +#define MV88E6250_CC_SHIFT 28 > > +#define MV88E6250_CC_MULT (10 << MV88E6250_CC_SHIFT) > > +#define MV88E6250_CC_MULT_NUM (1 << 7) > > +#define MV88E6250_CC_MULT_DEM 3125ULL > > + > > +/* Other families: > > + * Raw timestamps are in units of 8-ns clock periods. > > + * > > + * clkadj = scaled_ppm * 8*2^28 / (10^6 * 2^16) > > + * simplifies to > > + * clkadj = scaled_ppm * 2^9 / 5^6 > > + */ > > +#define MV88E6XXX_CC_SHIFT 28 > > +#define MV88E6XXX_CC_MULT (8 << MV88E6XXX_CC_SHIFT) > > +#define MV88E6XXX_CC_MULT_NUM (1 << 9) > > +#define MV88E6XXX_CC_MULT_DEM 15625ULL > > > > #define TAI_EVENT_WORK_INTERVAL msecs_to_jiffies(100) > > > > @@ -179,24 +206,14 @@ static void mv88e6352_tai_event_work(struct > > work_struct *ugly) > > static int mv88e6xxx_ptp_adjfine(struct ptp_clock_info *ptp, long > > scaled_ppm) > > { > > struct mv88e6xxx_chip *chip = ptp_to_chip(ptp); > > - int neg_adj = 0; > > - u32 diff, mult; > > - u64 adj; > > + s64 adj; > > > > - if (scaled_ppm < 0) { > > - neg_adj = 1; > > - scaled_ppm = -scaled_ppm; > > - } > > Please don't re-write this logic. It is written like that for a reason. I used the sja1105_ptp.c as a reference. So it is also wrong there. Hubert
