Cache the primary ice_hw pointer to ensure consistency between
calls (both parts of a value will be read from the same NAC).
ice_get_primary_hw() will never return NULL, but during the
ctrl_pf cleanup there may be a case when one call will return
the pointer to the ctrl_pf->hw and the subsequent one - to the
pf->hw which generally are not the same.
Struct ice_hw is embedded in the struct ice_pf so it is protected
by the same critical section - no additional synchronization is
needed.

Fixes: e2193f9f9ec9 ("ice: enable timesync operation on 2xNAC E825 devices")

Signed-off-by: Sergey Temerkhanov <[email protected]>
Reviewed-by: Aleksandr Loktionov <[email protected]>
Reviewed-by: Arkadiusz Kubalewski <[email protected]>
Tested-by: Frederick Lawler <[email protected]>
---
 drivers/net/ethernet/intel/ice/ice_ptp_hw.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c 
b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
index 3cb05879cb3f..2755e33f9203 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
@@ -4,6 +4,7 @@
 #include <linux/cleanup.h>
 #include <linux/delay.h>
 #include <linux/iopoll.h>
+#include "ice.h"
 #include "ice_common.h"
 #include "ice_ptp_hw.h"
 #include "ice_ptp_consts.h"
@@ -1943,10 +1944,14 @@ static int ice_read_phy_and_phc_time_eth56g(struct 
ice_hw *hw, u8 port,
                zo = rd32(hw, GLTSYN_SHTIME_0(tmr_idx));
                lo = rd32(hw, GLTSYN_SHTIME_L(tmr_idx));
        } else {
+               struct ice_hw *pri_hw;
+
                guard(rcu)();
 
-               zo = rd32(ice_get_primary_hw(pf), GLTSYN_SHTIME_0(tmr_idx));
-               lo = rd32(ice_get_primary_hw(pf), GLTSYN_SHTIME_L(tmr_idx));
+               pri_hw = ice_get_primary_hw(pf);
+
+               zo = rd32(pri_hw, GLTSYN_SHTIME_0(tmr_idx));
+               lo = rd32(pri_hw, GLTSYN_SHTIME_L(tmr_idx));
        }
        *phc_time = (u64)lo << 32 | zo;
 
@@ -2114,10 +2119,14 @@ int ice_start_phy_timer_eth56g(struct ice_hw *hw, u8 
port)
                lo = rd32(hw, GLTSYN_INCVAL_L(tmr_idx));
                hi = rd32(hw, GLTSYN_INCVAL_H(tmr_idx));
        } else {
+               struct ice_hw *pri_hw;
+
                guard(rcu)();
 
-               lo = rd32(ice_get_primary_hw(pf), GLTSYN_INCVAL_L(tmr_idx));
-               hi = rd32(ice_get_primary_hw(pf), GLTSYN_INCVAL_H(tmr_idx));
+               pri_hw = ice_get_primary_hw(pf);
+
+               lo = rd32(pri_hw, GLTSYN_INCVAL_L(tmr_idx));
+               hi = rd32(pri_hw, GLTSYN_INCVAL_H(tmr_idx));
        }
        incval = (u64)hi << 32 | lo;
 
-- 
2.53.0

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