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From: Giuseppe CAVALLARO <peppe.cavallaro@st•com>
To: Jimmy Perchet <jimmy.perchet@parrot•com>
Cc: <netdev@vger•kernel.org>
Subject: Re: [PATCH RFC 3/5] net:stmmac: ensure we reclaim all dirty descriptors.
Date: Mon, 21 Oct 2013 11:07:53 +0200	[thread overview]
Message-ID: <5264EEE9.8070607@st.com> (raw)
In-Reply-To: <1381937052-8999-4-git-send-email-jimmy.perchet@parrot.com>

Hello Jimmy

On 10/16/2013 5:24 PM, Jimmy Perchet wrote:
> On low speed link (10MBit/s), some TX descriptors can remain dirty
> if the tx coalescence timer expires before they were treated. Re-arm timer
> in this case.
>
> Signed-off-by: Jimmy Perchet <jimmy.perchet@parrot•com>
> ---
>   drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 0015175..af04b5d 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -1284,8 +1284,12 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
>   			p = priv->dma_tx + entry;
>
>   		/* Check if the descriptor is owned by the DMA. */
> -		if (priv->hw->desc->get_tx_owner(p))
> +		if (priv->hw->desc->get_tx_owner(p)) {
> +			/* Be sure to harvest remaining descriptor. */
> +			mod_timer(&priv->txtimer,
> +			  STMMAC_COAL_TIMER(priv->tx_coal_timer));
>   			break;
> +		}


why should we reload the timer when clean the tx resource?
This is done in the xmit where as soon as a frame has to be
transmitted it makes sense to reload the timer.

Also I have not clear why the problem happens on 10MBit/s speed
  Maybe there is an hidden problem (lock protection)
that should be fixed.

How did you get this problem? Just on low speed and stress the net?
I have never seen it.

peppe

>
>   		/* Verify tx error by looking at the last segment. */
>   		last = priv->hw->desc->get_tx_ls(p);
>

  parent reply	other threads:[~2013-10-21  9:07 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-16 15:24 [PATCH RFC 0/5] net:stmmac: fix jumbo frames handling and optimisation Jimmy Perchet
2013-10-16 15:24 ` [PATCH RFC 1/5] net:stmmac: set threshold/store and forward mode according to mtu size Jimmy Perchet
2013-10-21  8:47   ` Giuseppe CAVALLARO
2013-10-21  9:58     ` Rayagond K
2013-10-21 13:49       ` Giuseppe CAVALLARO
2013-10-16 15:24 ` [PATCH RFC 2/5] net:stmmac: fix rx buffer allocation Jimmy Perchet
2013-10-21  8:54   ` Giuseppe CAVALLARO
2013-10-16 15:24 ` [PATCH RFC 3/5] net:stmmac: ensure we reclaim all dirty descriptors Jimmy Perchet
2013-10-16 17:46   ` Sergei Shtylyov
2013-10-18  8:32     ` Jimmy PERCHET
2013-10-21  9:07   ` Giuseppe CAVALLARO [this message]
2013-10-21 13:10     ` Jimmy PERCHET
2013-10-21 18:32       ` Eric Dumazet
2013-10-21 18:49         ` Eric Dumazet
2013-10-22 13:33           ` Giuseppe CAVALLARO
2013-10-16 15:24 ` [PATCH RFC 4/5] net:stmmac: fix jumbo frame handling Jimmy Perchet
2013-10-21 13:40   ` Giuseppe CAVALLARO
2013-10-21 16:28     ` Jimmy PERCHET
2013-10-22 13:24       ` Giuseppe CAVALLARO
2013-10-16 15:24 ` [PATCH RFC 5/5] net:stmmac: asynchronous tx_clean Jimmy Perchet
2013-10-21 13:52   ` Giuseppe CAVALLARO
2013-10-21 16:30     ` Eric Dumazet
2013-10-21 18:05       ` Jimmy PERCHET
2013-10-21 18:24         ` Eric Dumazet
2013-10-16 20:37 ` [PATCH RFC 0/5] net:stmmac: fix jumbo frames handling and optimisation Giuseppe CAVALLARO
2013-10-18 16:24   ` Jimmy PERCHET

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