[PATCH 3.11 008/233] sfc: Maintain current frequency adjustment when applying a time offset

[Luis Henriques]

3.11.10.4 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ben Hutchings <bhutchings at solarflare.com>

commit cd6fe65e923175e4f2e9fb585b1d78c6bf580fc6 upstream.

There is a single MCDI PTP operation for setting the frequency
adjustment and applying a time offset to the hardware clock.  When
applying a time offset we should not change the frequency adjustment.

These two operations can now be requested separately but this requires
a flash firmware update.  Keep using the single operation, but
remember and repeat the previous frequency adjustment.

Fixes: 7c236c43b838 ('sfc: Add support for IEEE-1588 PTP')
Signed-off-by: Ben Hutchings <bhutchings at solarflare.com>
[ luis: backported to 3.11:
  - replaced MCDI_SET_QWORD() by 2x MCDI_SET_DWORD() ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/ethernet/sfc/ptp.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index b24d3be..11d979d 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -1420,7 +1420,7 @@ static int efx_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta)
 	if (rc != 0)
 		return rc;
 
-	ptp_data->current_adjfreq = delta;
+	ptp_data->current_adjfreq = adjustment_ns;
 	return 0;
 }
 
@@ -1434,8 +1434,9 @@ static int efx_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
 	u8 inbuf[MC_CMD_PTP_IN_ADJUST_LEN];
 
 	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_ADJUST);
-	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_FREQ_LO, 0);
-	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_FREQ_HI, 0);
+	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_FREQ_LO, (u32)ptp_data->current_adjfreq);
+	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_FREQ_HI,
+		       (u32)(ptp_data->current_adjfreq >> 32));
 	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_SECONDS, (u32)delta_ts.tv_sec);
 	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_NANOSECONDS, (u32)delta_ts.tv_nsec);
 	return efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
-- 
1.8.3.2