In mpt3sas_base_clear_st() function smid value is reseted in wrong line, i.e. driver should reset smid value to zero after decrementing chain_offset counter in chain_lookup table but in current code, driver is resetting smid value before decrementing the chain_offset counter. which we are correcting with this patch. v1 changelog: Added memory barriers before & after atomic_set() API. Signed-off-by: Sreekanth Reddy <sreekanth.reddy@xxxxxxxxxxxx> --- drivers/scsi/mpt3sas/mpt3sas_base.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c index 902610d..94359d8 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_base.c +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c @@ -1702,6 +1702,8 @@ static int mpt3sas_remove_dead_ioc_func(void *arg) return NULL; chain_req = &ioc->chain_lookup[smid - 1].chains_per_smid[chain_offset]; + /* Adding memory barrier before atomic operation. */ + smp_mb__before_atomic(); atomic_inc(&ioc->chain_lookup[smid - 1].chain_offset); return chain_req; } @@ -3283,8 +3285,12 @@ void mpt3sas_base_clear_st(struct MPT3SAS_ADAPTER *ioc, return; st->cb_idx = 0xFF; st->direct_io = 0; - st->smid = 0; + /* Adding memory barrier before atomic operation. */ + smp_mb__before_atomic(); atomic_set(&ioc->chain_lookup[st->smid - 1].chain_offset, 0); + /* Adding memory barrier after atomic operation. */ + smp_mb__after_atomic(); + st->smid = 0; } /** -- 1.8.3.1
