RE: [net-next 07/12] ixgbe: Enable timesync clock-out feature for PPS support on X540

-----Original Message-----
From: Richard Cochran [mailto:richardcochran@gmail.com]
Sent: Thursday, May 10, 2012 7:17 AM
To: Kirsher, Jeffrey T
Cc: davem@davemloft.net; Keller, Jacob E; netdev@vger.kernel.org;
gospo@redhat.com; sassmann@redhat.com
Subject: Re: [net-next 07/12] ixgbe: Enable timesync clock-out feature for PPS
support on X540

On Wed, May 09, 2012 at 11:46:48PM -0700, Jeff Kirsher wrote:

quoted

From: Jacob E Keller <jacob.e.keller@intel.com>

This patch enables the PPS system in the PHC framework, by enabling
the clock-out feature on the X540 device. Causes the SDP0 to be set as
a 1Hz clock. Also configures the timesync interrupt cause in order to
report each pulse to the PPS via the PHC framework, which can be used
for general system clock synchronization. (This allows a stable method
for tuning the general system time via the on-board SYSTIM register
based clock.)

Glad to see the PPS output and internal PPS support.

quoted

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 9a83c40..1ad6e2a 100644

--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

...

quoted

 /**
+ * ixgbe_ptp_check_pps_event
+ * @adapter - the private adapter structure
+ * @eicr - the interrupt cause register value
+ *
+ * This function is called by the interrupt routine when checking for
+ * interrupts. It will check and handle a pps event.
+ */
+void ixgbe_ptp_check_pps_event(struct ixgbe_adapter *adapter, u32
+eicr) {
+	struct ixgbe_hw *hw = &adapter->hw;
+	struct ptp_clock_event event;
+
+	event.type = PTP_CLOCK_PPS;
+
+	/* Make sure ptp clock is valid, and PPS event enabled */
+	if (!adapter->ptp_clock ||
+	    !(adapter->flags2 & IXGBE_FLAG2_PTP_PPS_ENABLED))
+		return;
+
+	switch (hw->mac.type) {
+	case ixgbe_mac_X540:
+		if (eicr & IXGBE_EICR_TIMESYNC)

Since this function is called in every interrupt, I would check this flag
first thing.

Not sure what you mean? Check this before checking the other interrupts?
I can do that.

quoted

+			ptp_clock_event(adapter->ptp_clock, &event);
+		break;
+	default:
+		break;
+	}
+}

Thanks,
Richard