4.19-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit fa0be0a43f101888ac677dba31b590963eafeaa1 ]
Currently, TX is given a budget which is consumed by stmmac_tx_clean() and stmmac_rx() is given the remaining non-consumed budget.
This is wrong and in case we are sending a large number of packets this can starve RX because remaining budget will be low.
Let's give always the same budget for RX and TX clean.
While at it, check if we missed any interrupts while we were in NAPI callback by looking at DMA interrupt status.
Cc: Joao Pinto jpinto@synopsys.com Cc: David S. Miller davem@davemloft.net Cc: Giuseppe Cavallaro peppe.cavallaro@st.com Cc: Alexandre Torgue alexandre.torgue@st.com Signed-off-by: Jose Abreu joabreu@synopsys.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- .../net/ethernet/stmicro/stmmac/stmmac_main.c | 27 ++++++++++--------- 1 file changed, 14 insertions(+), 13 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 24ae244c2ee33..123b74e25ed81 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -3522,27 +3522,28 @@ static int stmmac_napi_poll(struct napi_struct *napi, int budget) struct stmmac_channel *ch = container_of(napi, struct stmmac_channel, napi); struct stmmac_priv *priv = ch->priv_data; - int work_done = 0, work_rem = budget; + int work_done, rx_done = 0, tx_done = 0; u32 chan = ch->index;
priv->xstats.napi_poll++;
- if (ch->has_tx) { - int done = stmmac_tx_clean(priv, work_rem, chan); + if (ch->has_tx) + tx_done = stmmac_tx_clean(priv, budget, chan); + if (ch->has_rx) + rx_done = stmmac_rx(priv, budget, chan);
- work_done += done; - work_rem -= done; - } - - if (ch->has_rx) { - int done = stmmac_rx(priv, work_rem, chan); + work_done = max(rx_done, tx_done); + work_done = min(work_done, budget);
- work_done += done; - work_rem -= done; - } + if (work_done < budget && napi_complete_done(napi, work_done)) { + int stat;
- if (work_done < budget && napi_complete_done(napi, work_done)) stmmac_enable_dma_irq(priv, priv->ioaddr, chan); + stat = stmmac_dma_interrupt_status(priv, priv->ioaddr, + &priv->xstats, chan); + if (stat && napi_reschedule(napi)) + stmmac_disable_dma_irq(priv, priv->ioaddr, chan); + }
return work_done; }