| Message ID | 1421001138.5947.100.camel@edumazet-glaptop2.roam.corp.google.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Sun, 11 Jan 2015 10:32:18 -0800 > From: Eric Dumazet <edumazet@google.com> > > Commit d75b1ade567f ("net: less interrupt masking in NAPI") uncovered > wrong alx_poll() behavior. > > A NAPI poll() handler is supposed to return exactly the budget when/if > napi_complete() has not been called. > > It is also supposed to return number of frames that were received, so > that netdev_budget can have a meaning. > > Also, in case of TX pressure, we still have to dequeue received > packets : alx_clean_rx_irq() has to be called even if > alx_clean_tx_irq(alx) returns false, otherwise device is half duplex. > > Signed-off-by: Eric Dumazet <edumazet@google.com> > Fixes: d75b1ade567f ("net: less interrupt masking in NAPI") > Reported-by: Oded Gabbay <oded.gabbay@amd.com> > Bisected-by: Oded Gabbay <oded.gabbay@amd.com> > Tested-by: Oded Gabbay <oded.gabbay@amd.com> Applied and queued up for -stable, thanks Eric. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, 2015-01-11 at 18:32 +0000, Eric Dumazet wrote: > Commit d75b1ade567f ("net: less interrupt masking in NAPI") uncovered > wrong alx_poll() behavior. [...] Thanks Eric and Oded! :) johannes -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/ethernet/atheros/alx/main.c b/drivers/net/ethernet/atheros/alx/main.c index e398eda07298..c8af3ce3ea38 100644 --- a/drivers/net/ethernet/atheros/alx/main.c +++ b/drivers/net/ethernet/atheros/alx/main.c @@ -184,15 +184,16 @@ static void alx_schedule_reset(struct alx_priv *alx) schedule_work(&alx->reset_wk); } -static bool alx_clean_rx_irq(struct alx_priv *alx, int budget) +static int alx_clean_rx_irq(struct alx_priv *alx, int budget) { struct alx_rx_queue *rxq = &alx->rxq; struct alx_rrd *rrd; struct alx_buffer *rxb; struct sk_buff *skb; u16 length, rfd_cleaned = 0; + int work = 0; - while (budget > 0) { + while (work < budget) { rrd = &rxq->rrd[rxq->rrd_read_idx]; if (!(rrd->word3 & cpu_to_le32(1 << RRD_UPDATED_SHIFT))) break; @@ -203,7 +204,7 @@ static bool alx_clean_rx_irq(struct alx_priv *alx, int budget) ALX_GET_FIELD(le32_to_cpu(rrd->word0), RRD_NOR) != 1) { alx_schedule_reset(alx); - return 0; + return work; } rxb = &rxq->bufs[rxq->read_idx]; @@ -243,7 +244,7 @@ static bool alx_clean_rx_irq(struct alx_priv *alx, int budget) } napi_gro_receive(&alx->napi, skb); - budget--; + work++; next_pkt: if (++rxq->read_idx == alx->rx_ringsz) @@ -258,21 +259,22 @@ next_pkt: if (rfd_cleaned) alx_refill_rx_ring(alx, GFP_ATOMIC); - return budget > 0; + return work; } static int alx_poll(struct napi_struct *napi, int budget) { struct alx_priv *alx = container_of(napi, struct alx_priv, napi); struct alx_hw *hw = &alx->hw; - bool complete = true; unsigned long flags; + bool tx_complete; + int work; - complete = alx_clean_tx_irq(alx) && - alx_clean_rx_irq(alx, budget); + tx_complete = alx_clean_tx_irq(alx); + work = alx_clean_rx_irq(alx, budget); - if (!complete) - return 1; + if (!tx_complete || work == budget) + return budget; napi_complete(&alx->napi); @@ -284,7 +286,7 @@ static int alx_poll(struct napi_struct *napi, int budget) alx_post_write(hw); - return 0; + return work; } static irqreturn_t alx_intr_handle(struct alx_priv *alx, u32 intr)