From 3b65802e4c5a8827a84022066f10dec4d61c1f22 Mon Sep 17 00:00:00 2001 From: Erwan Velu Date: Mon, 7 May 2012 14:53:17 +0200 Subject: [PATCH 1/1] pch_gbe: Adding read memory barriers Under a strong incoming packet stream and/or high cpu usage, the pch_gbe driver reports "Receive CRC Error" and discards packet. Adding rmb() calls before considering the network card's status solve this issues. Signed-off-by: Erwan Velu --- .../net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c index 48406ca..7746ca3 100644 --- a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c +++ b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c @@ -1222,6 +1222,8 @@ static irqreturn_t pch_gbe_intr(int irq, void *data) } } + smp_rmb(); /* prevent any other reads before*/ + /* When request status is Receive interruption */ if ((int_st & (PCH_GBE_INT_RX_DMA_CMPLT | PCH_GBE_INT_TX_CMPLT)) || (adapter->rx_stop_flag == true)) { @@ -1390,6 +1392,9 @@ pch_gbe_clean_tx(struct pch_gbe_adapter *adapter, i = tx_ring->next_to_clean; tx_desc = PCH_GBE_TX_DESC(*tx_ring, i); + + rmb(); /* prevent any other reads before*/ + pr_debug("gbec_status:0x%04x dma_status:0x%04x\n", tx_desc->gbec_status, tx_desc->dma_status); @@ -1490,6 +1495,9 @@ pch_gbe_clean_rx(struct pch_gbe_adapter *adapter, while (*work_done < work_to_do) { /* Check Rx descriptor status */ rx_desc = PCH_GBE_RX_DESC(*rx_ring, i); + + rmb(); /* prevent any other reads before*/ + if (rx_desc->gbec_status == DSC_INIT16) break; cleaned = true; -- 1.7.4.4