From 097c317afe0a582cfbf04506f368ee3a3ad0ae74 Mon Sep 17 00:00:00 2001 From: Karol Kolacinski Date: Tue, 25 Jul 2023 14:50:47 -0700 Subject: [PATCH] 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: Karol Kolacinski Signed-off-by: Jacob Keller Tested-by: Pucha Himasekhar Reddy (A Contingent worker at Intel) Signed-off-by: Tony Nguyen --- drivers/net/ethernet/intel/ice/ice_ptp.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c index 81d96a40d5a74..e75bb6e7d680d 100644 --- a/drivers/net/ethernet/intel/ice/ice_ptp.c +++ b/drivers/net/ethernet/intel/ice/ice_ptp.c @@ -1976,11 +1976,21 @@ ice_ptp_get_syncdevicetime(ktime_t *device, u32 hh_lock, hh_art_ctl; int i; - /* Get the HW lock */ - hh_lock = rd32(hw, PFHH_SEM + (PFTSYN_SEM_BYTES * hw->pf_id)); +#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;