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ptp: ocp: Add ptp_ocp_adjtime_coarse for large adjustments

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In ("ptp: ocp: Have FPGA fold in ns adjustment for adjtime."), the
ns adjustment was written to the FPGA register, so the clock could
accurately perform adjustments.

However, the adjtime() call passes in a s64, while the clock adjustment
registers use a s32.  When trying to perform adjustments with a large
value (37 sec), things fail.

Examine the incoming delta, and if larger than 1 sec, use the original
(coarse) adjustment method.  If smaller than 1 sec, then allow the
FPGA to fold in the changes over a 1 second window.

Fixes: 6d59d4fa17 ("ptp: ocp: Have FPGA fold in ns adjustment for adjtime.")
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Link: https://lore.kernel.org/r/20220228203957.367371-1-jonathan.lemon@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jonathan Lemon 2022-02-28 12:39:57 -08:00 committed by Jakub Kicinski
parent 0b0e2ff103
commit 90f8f4c0e3
1 changed files with 23 additions and 2 deletions
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25
drivers/ptp/ptp_ocp.c
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@ -607,7 +607,7 @@ ptp_ocp_settime(struct ptp_clock_info *ptp_info, const struct timespec64 *ts)
}
static void
__ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u64 adj_val)
__ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u32 adj_val)
{
u32 select, ctrl;
@ -615,7 +615,7 @@ __ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u64 adj_val)
iowrite32(OCP_SELECT_CLK_REG, &bp->reg->select);
iowrite32(adj_val, &bp->reg->offset_ns);
iowrite32(adj_val & 0x7f, &bp->reg->offset_window_ns);
iowrite32(NSEC_PER_SEC, &bp->reg->offset_window_ns);
ctrl = OCP_CTRL_ADJUST_OFFSET | OCP_CTRL_ENABLE;
iowrite32(ctrl, &bp->reg->ctrl);
@ -624,6 +624,22 @@ __ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u64 adj_val)
iowrite32(select >> 16, &bp->reg->select);
}
static void
ptp_ocp_adjtime_coarse(struct ptp_ocp *bp, u64 delta_ns)
{
struct timespec64 ts;
unsigned long flags;
int err;
spin_lock_irqsave(&bp->lock, flags);
err = __ptp_ocp_gettime_locked(bp, &ts, NULL);
if (likely(!err)) {
timespec64_add_ns(&ts, delta_ns);
__ptp_ocp_settime_locked(bp, &ts);
}
spin_unlock_irqrestore(&bp->lock, flags);
}
static int
ptp_ocp_adjtime(struct ptp_clock_info *ptp_info, s64 delta_ns)
{
@ -631,6 +647,11 @@ ptp_ocp_adjtime(struct ptp_clock_info *ptp_info, s64 delta_ns)
unsigned long flags;
u32 adj_ns, sign;
if (delta_ns > NSEC_PER_SEC || -delta_ns > NSEC_PER_SEC) {
ptp_ocp_adjtime_coarse(bp, delta_ns);
return 0;
}
sign = delta_ns < 0 ? BIT(31) : 0;
adj_ns = sign ? -delta_ns : delta_ns;