[dpdk-dev] [PATCH 02/10] net/enetc: use relaxed read for Tx CI in clean Tx
Hemant Agrawal
hemant.agrawal at nxp.com
Mon Mar 2 15:32:01 CET 2020
From: Alex Marginean <alexandru.marginean at nxp.com>
We don't need barriers here since this read doesn't have to be strictly
serialized in relation to other surrounding memory/register accesses.
We only want a reasonably recent value out of hardware so we know how much
we can clean.
Signed-off-by: Alex Marginean <alexandru.marginean at nxp.com>
---
drivers/net/enetc/enetc_rxtx.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/net/enetc/enetc_rxtx.c b/drivers/net/enetc/enetc_rxtx.c
index b7ecb75ec..395f5ecf4 100644
--- a/drivers/net/enetc/enetc_rxtx.c
+++ b/drivers/net/enetc/enetc_rxtx.c
@@ -23,12 +23,15 @@ enetc_clean_tx_ring(struct enetc_bdr *tx_ring)
struct enetc_swbd *tx_swbd;
int i, hwci;
+ /* we don't need barriers here, we just want a relatively current value
+ * from HW.
+ */
+ hwci = (int)(rte_read32_relaxed(tx_ring->tcisr) &
+ ENETC_TBCISR_IDX_MASK);
+
i = tx_ring->next_to_clean;
tx_swbd = &tx_ring->q_swbd[i];
- hwci = (int)(enetc_rd_reg(tx_ring->tcisr) &
- ENETC_TBCISR_IDX_MASK);
-
/* we're only reading the CI index once here, which means HW may update
* it while we're doing clean-up. We could read the register in a loop
* but for now I assume it's OK to leave a few Tx frames for next call.
--
2.17.1
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