[PATCH v4 090/103] net/ice/base: cleanup timestamp registers correctly

[Anatoly Burakov]

From: Karol Kolacinski <karol.kolacinski at intel.com>

E822 PHY TS registers should not be written and the only way to cleanup
them is to reset QUAD memory.

To ensure that the status bit for the timestamp index is cleared, ensure
that ice_clear_phy_tstamp implementations first read the timestamp out.
Implementations which can write the register continue to do so.

Add a note to indicate this function should only be called on timestamps
which have their valid bit set.

Signed-off-by: Karol Kolacinski <karol.kolacinski at intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller at intel.com>
Signed-off-by: Ian Stokes <ian.stokes at intel.com>
---
 drivers/net/ice/base/ice_ptp_hw.c | 46 ++++++++++++++++++-------------
 1 file changed, 27 insertions(+), 19 deletions(-)

diff --git a/drivers/net/ice/base/ice_ptp_hw.c b/drivers/net/ice/base/ice_ptp_hw.c
index bf3c32ae64..bba228ed39 100644
--- a/drivers/net/ice/base/ice_ptp_hw.c
+++ b/drivers/net/ice/base/ice_ptp_hw.c
@@ -1540,8 +1540,18 @@ static int
 ice_clear_phy_tstamp_eth56g(struct ice_hw *hw, u8 port, u8 idx)
 {
 	int err;
+	u64 unused_tstamp;
 	u16 lo_addr;
 
+	/* Read the timestamp register to ensure the timestamp status bit is
+	 * cleared.
+	 */
+	err = ice_read_phy_tstamp_eth56g(hw, port, idx, &unused_tstamp);
+	if (err) {
+		ice_debug(hw, ICE_DBG_PTP, "Failed to read the PHY timestamp register for port %u, idx %u, err %d\n",
+			  port, idx, err);
+	}
+
 	lo_addr = (u16)PHY_TSTAMP_L(idx);
 
 	err = ice_phy_port_mem_write_eth56g(hw, port, lo_addr, 0);
@@ -2997,23 +3007,13 @@ ice_read_phy_tstamp_e822(struct ice_hw *hw, u8 quad, u8 idx, u64 *tstamp)
 static int
 ice_clear_phy_tstamp_e822(struct ice_hw *hw, u8 quad, u8 idx)
 {
+	u64 unused_tstamp;
 	int err;
-	u16 lo_addr, hi_addr;
 
-	lo_addr = (u16)TS_L(Q_REG_TX_MEMORY_BANK_START, idx);
-	hi_addr = (u16)TS_H(Q_REG_TX_MEMORY_BANK_START, idx);
-
-	err = ice_write_quad_reg_e822(hw, quad, lo_addr, 0);
-	if (err) {
-		ice_debug(hw, ICE_DBG_PTP, "Failed to clear low PTP timestamp register, err %d\n",
-			  err);
-		return err;
-	}
-
-	err = ice_write_quad_reg_e822(hw, quad, hi_addr, 0);
+	err = ice_read_phy_tstamp_e822(hw, quad, idx, &unused_tstamp);
 	if (err) {
-		ice_debug(hw, ICE_DBG_PTP, "Failed to clear high PTP timestamp register, err %d\n",
-			  err);
+		ice_debug(hw, ICE_DBG_PTP, "Failed to read the timestamp register for quad %u, idx %u, err %d\n",
+			  quad, idx, err);
 		return err;
 	}
 
@@ -4939,23 +4939,31 @@ ice_read_phy_tstamp_e810(struct ice_hw *hw, u8 lport, u8 idx, u64 *tstamp)
 static int
 ice_clear_phy_tstamp_e810(struct ice_hw *hw, u8 lport, u8 idx)
 {
-	int err;
 	u32 lo_addr, hi_addr;
+	u64 unused_tstamp;
+	int err;
+
+	err = ice_read_phy_tstamp_e810(hw, lport, idx, &unused_tstamp);
+	if (err) {
+		ice_debug(hw, ICE_DBG_PTP, "Failed to read the timestamp register for lport %u, idx %u, err %d\n",
+			  lport, idx, err);
+		return err;
+	}
 
 	lo_addr = TS_EXT(LOW_TX_MEMORY_BANK_START, lport, idx);
 	hi_addr = TS_EXT(HIGH_TX_MEMORY_BANK_START, lport, idx);
 
 	err = ice_write_phy_reg_e810(hw, lo_addr, 0);
 	if (err) {
-		ice_debug(hw, ICE_DBG_PTP, "Failed to clear low PTP timestamp register, err %d\n",
-			  err);
+		ice_debug(hw, ICE_DBG_PTP, "Failed to clear low PTP timestamp register for lport %u, idx %u, err %d\n",
+			  lport, idx, err);
 		return err;
 	}
 
 	err = ice_write_phy_reg_e810(hw, hi_addr, 0);
 	if (err) {
-		ice_debug(hw, ICE_DBG_PTP, "Failed to clear high PTP timestamp register, err %d\n",
-			  err);
+		ice_debug(hw, ICE_DBG_PTP, "Failed to clear high PTP timestamp register for lport %u, idx %u, err %d\n",
+			  lport, idx, err);
 		return err;
 	}
 
-- 
2.43.0