From 31bafc49a7736989e4c2d9f7280002c66536e590 Mon Sep 17 00:00:00 2001 From: Igor Russkikh Date: Sat, 25 May 2019 09:57:59 +0000 Subject: net: aquantia: tx clean budget logic error In case no other traffic happening on the ring, full tx cleanup may not be completed. That may cause socket buffer to overflow and tx traffic to stuck until next activity on the ring happens. This is due to logic error in budget variable decrementor. Variable is compared with zero, and then post decremented, causing it to become MAX_INT. Solution is remove decrementor from the `for` statement and rewrite it in a clear way. Fixes: b647d3980948e ("net: aquantia: Add tx clean budget and valid budget handling logic") Signed-off-by: Igor Russkikh Signed-off-by: David S. Miller --- drivers/net/ethernet/aquantia/atlantic/aq_ring.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers/net/ethernet/aquantia') diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c index 350e385528fd..63ed00415904 100644 --- a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c +++ b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c @@ -223,10 +223,10 @@ void aq_ring_queue_stop(struct aq_ring_s *ring) bool aq_ring_tx_clean(struct aq_ring_s *self) { struct device *dev = aq_nic_get_dev(self->aq_nic); - unsigned int budget = AQ_CFG_TX_CLEAN_BUDGET; + unsigned int budget; - for (; self->sw_head != self->hw_head && budget--; - self->sw_head = aq_ring_next_dx(self, self->sw_head)) { + for (budget = AQ_CFG_TX_CLEAN_BUDGET; + budget && self->sw_head != self->hw_head; budget--) { struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head]; if (likely(buff->is_mapped)) { @@ -251,6 +251,7 @@ bool aq_ring_tx_clean(struct aq_ring_s *self) buff->pa = 0U; buff->eop_index = 0xffffU; + self->sw_head = aq_ring_next_dx(self, self->sw_head); } return !!budget; -- cgit v1.2.3-59-g8ed1b