[PATCH net v2 3/3] ptp: qoriq: fix support for PTP_EXTTS_REQUEST2 ioctl

[Vincent Jardin via B4 Relay]

From: Vincent Jardin <vjardin@xxxxxxx>

Commit 7c571ac57d9d ("net: ptp: introduce .supported_extts_flags to
ptp_clock_info") moved the validation of the external timestamp request
flags into the PTP core. A driver that does not set
.supported_extts_flags still accepts the legacy PTP_EXTTS_REQUEST ioctl,
but every PTP_EXTTS_REQUEST2 request is rejected with -EOPNOTSUPP, since
the core always adds PTP_STRICT_FLAGS to it.

ptp_qoriq_init() programs TMR_CTRL with ETEP1 and ETEP2 cleared, so the
timer timestamps the rising edge of its external trigger inputs. Declare
that, with PTP_STRICT_FLAGS, so that a falling edge request is rejected
instead of being timestamped on the rising edge.

This also makes the legacy PTP_EXTTS_REQUEST ioctl strict: a request for
the falling edge, or for both edges, now fails with -EOPNOTSUPP instead
of being timestamped on the rising edge. That cannot be avoided: the core
adds PTP_STRICT_FLAGS to every PTP_EXTTS_REQUEST2 request, so a driver
has to declare it to accept them, and once declared it applies to both
ioctls. Commit 3200fdd4021d ("broadcom: fix support for
PTP_EXTTS_REQUEST2 ioctl") made the same change for bcm-phy-ptp.

Fixes: 7c571ac57d9d ("net: ptp: introduce .supported_extts_flags to ptp_clock_info")
Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>
Reviewed-by: Kory Maincent <kory.maincent@xxxxxxxxxxx>
Signed-off-by: Vincent Jardin <vjardin@xxxxxxx>
---
 drivers/ptp/ptp_qoriq.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/ptp/ptp_qoriq.c b/drivers/ptp/ptp_qoriq.c
index 76272e5ac5b8..bcd29104effe 100644
--- a/drivers/ptp/ptp_qoriq.c
+++ b/drivers/ptp/ptp_qoriq.c
@@ -355,6 +355,7 @@ static const struct ptp_clock_info ptp_qoriq_caps = {
 	.n_per_out	= 0,
 	.n_pins		= 0,
 	.pps		= 1,
+	.supported_extts_flags = PTP_RISING_EDGE | PTP_STRICT_FLAGS,
 	.adjfine	= ptp_qoriq_adjfine,
 	.adjtime	= ptp_qoriq_adjtime,
 	.gettime64	= ptp_qoriq_gettime,

-- 
2.43.0