ice: exit bypass mode once hardware finishes timestamp calibration

Once the E822 device has sent and received one packet, the hardware
computes the internal delay of the PHY using a process known as Vernier
calibration. This calibration calculates a more accurate offset for the
Tx and Rx timestamps. To make use of this offset, we need to exit the
bypass mode. This cannot be done until the PHY has completed offset
calibration, as indicated by the offset valid bits.

To handle this, introduce a kthread work item which will poll the offset
valid bits every few milliseconds seeing if it is safe to exit bypass
mode.

Once we have finished calibrating the offsets, we can program the total
Tx and Rx offset registers and turn off the bypass bit. This allows the
hardware to include the more precise vernier calibration offset, and
improves the timestamp precision.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.h b/drivers/net/ethernet/intel/ice/ice_ptp.h
index a110c81d4772..afd048d69959 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.h
@@ -109,14 +109,18 @@ struct ice_ptp_tx {
  * and determine when the port's PHY offset is valid.
  *
  * @tx: Tx timestamp tracking for this port
+ * @ov_work: delayed work task for tracking when PHY offset is valid
  * @ps_lock: mutex used to protect the overall PTP PHY start procedure
  * @link_up: indicates whether the link is up
+ * @tx_fifo_busy_cnt: number of times the Tx FIFO was busy
  * @port_num: the port number this structure represents
  */
 struct ice_ptp_port {
 	struct ice_ptp_tx tx;
+	struct kthread_delayed_work ov_work;
 	struct mutex ps_lock; /* protects overall PTP PHY start procedure */
 	bool link_up;
+	u8 tx_fifo_busy_cnt;
 	u8 port_num;
 };