Commit 097c317a authored by Karol Kolacinski's avatar Karol Kolacinski Committed by Tony Nguyen
Browse files

ice: retry acquiring hardware semaphore during cross-timestamp request 



The hardware for performing a cross-timestamp on E822 uses a hardware
semaphore which we must acquire before initiating the cross-timestamp
operation.

The current implementation only attempts to acquire the semaphore once, and
assumes that it will succeed. If the semaphore is busy for any reason, the
cross-timestamp operation fails with -EFAULT.

Instead of immediately failing, try the acquire the lock a few times with a
small sleep between attempts. This ensures that most requests will go
through without issue.

Additionally, return -EBUSY instead of -EFAULT if the operation can't
continue due to the semaphore being busy.

Signed-off-by: default avatarKarol Kolacinski <karol.kolacinski@intel.com>
Signed-off-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
parent 40326b2b

drivers/net/ethernet/intel/ice/ice_ptp.c

+15 −7
Original line number Diff line number Diff line
@@ -1976,11 +1976,21 @@ ice_ptp_get_syncdevicetime(ktime_t *device, 
	u32 hh_lock, hh_art_ctl;

	int i;



#define MAX_HH_HW_LOCK_TRIES	5

#define MAX_HH_CTL_LOCK_TRIES	100



	for (i = 0; i < MAX_HH_HW_LOCK_TRIES; i++) {

		/* Get the HW lock */

		hh_lock = rd32(hw, PFHH_SEM + (PFTSYN_SEM_BYTES * hw->pf_id));

		if (hh_lock & PFHH_SEM_BUSY_M) {

			usleep_range(10000, 15000);

			continue;

		}

		break;

	}

	if (hh_lock & PFHH_SEM_BUSY_M) {

		dev_err(ice_pf_to_dev(pf), "PTP failed to get hh lock\n");

		return -EFAULT;

		return -EBUSY;

	}



	/* Start the ART and device clock sync sequence */
@@ -1988,9 +1998,7 @@ ice_ptp_get_syncdevicetime(ktime_t *device, 
	hh_art_ctl = hh_art_ctl | GLHH_ART_CTL_ACTIVE_M;

	wr32(hw, GLHH_ART_CTL, hh_art_ctl);



#define MAX_HH_LOCK_TRIES 100



	for (i = 0; i < MAX_HH_LOCK_TRIES; i++) {

	for (i = 0; i < MAX_HH_CTL_LOCK_TRIES; i++) {

		/* Wait for sync to complete */

		hh_art_ctl = rd32(hw, GLHH_ART_CTL);

		if (hh_art_ctl & GLHH_ART_CTL_ACTIVE_M) {
@@ -2019,7 +2027,7 @@ ice_ptp_get_syncdevicetime(ktime_t *device, 
	hh_lock = hh_lock & ~PFHH_SEM_BUSY_M;

	wr32(hw, PFHH_SEM + (PFTSYN_SEM_BYTES * hw->pf_id), hh_lock);



	if (i == MAX_HH_LOCK_TRIES)

	if (i == MAX_HH_CTL_LOCK_TRIES)

		return -ETIMEDOUT;



	return 0;