| Message ID | 1dfd166fdfad67542e5e2ace11ee1983fe2ddf60.1526651009.git.joabreu@synopsys.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | net: stmmac: Clean-up and tune-up | expand |
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c index 117c3a5..9aab5b3 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c @@ -94,6 +94,10 @@ static void dwmac4_dma_init_tx_chan(void __iomem *ioaddr, value = readl(ioaddr + DMA_CHAN_TX_CONTROL(chan)); value = value | (txpbl << DMA_BUS_MODE_PBL_SHIFT); + + /* Enable OSP to get best performance */ + value |= DMA_CONTROL_OSP; + writel(value, ioaddr + DMA_CHAN_TX_CONTROL(chan)); writel(dma_tx_phy, ioaddr + DMA_CHAN_TX_BASE_ADDR(chan));
This enables OSP (Operate on Second Packet) for GMAC4. The feature allows DMA to fetch second descriptor while its still processing the first one. Running iperf, the performance gain is +/- 38%. Signed-off-by: Jose Abreu <joabreu@synopsys.com> Cc: David S. Miller <davem@davemloft.net> Cc: Joao Pinto <jpinto@synopsys.com> Cc: Vitor Soares <soares@synopsys.com> Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> --- drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-)