* [ECOS] ea2468 Ethernet overrun @ 2009-06-03 13:43 Nikolay Marusov 2009-06-03 13:55 ` Andrew Lunn 0 siblings, 1 reply; 3+ messages in thread From: Nikolay Marusov @ 2009-06-03 13:43 UTC (permalink / raw) To: ecos-discuss Hello! I am playing with Embedded Artists LPC2468-16 OEM Board. Has anybody encounetered with a problem of TX overrun while transmitting Ethernet packets? Device works pretty well at 10Mbit/s but regullarly drops packet when transmitting at 100Mbit/s. What may be the cause? Nikolay. -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [ECOS] ea2468 Ethernet overrun 2009-06-03 13:43 [ECOS] ea2468 Ethernet overrun Nikolay Marusov @ 2009-06-03 13:55 ` Andrew Lunn 2009-06-03 14:19 ` Nikolay Marusov 0 siblings, 1 reply; 3+ messages in thread From: Andrew Lunn @ 2009-06-03 13:55 UTC (permalink / raw) To: Nikolay Marusov; +Cc: ecos-discuss On Wed, Jun 03, 2009 at 05:43:04PM +0400, Nikolay Marusov wrote: > Hello! > > I am playing with Embedded Artists LPC2468-16 OEM Board. > Has anybody encounetered with a problem of TX overrun while > transmitting Ethernet packets? > Device works pretty well at 10Mbit/s but regullarly drops packet when > transmitting at 100Mbit/s. > What may be the cause? Is it an overrun or an underrun? I've seen underrun problems before in an intel chipset. The problem was that the DMA would start transferring the packet from the host RAM to the ethernet chipset. When X bytes of the packet had arrived at the ethernet, the ethernet started sending them on the wire. Under heavy memory load, the DMA was slower than the Ethernet sending bytes on the wire, and with long packets the ethernet chip would empty its buffer and then throw an underrun error. I had the change the Ethernet chipset to have a bigger X so it had more buffered bytes before it started sending them to the wire. Andrew -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [ECOS] ea2468 Ethernet overrun 2009-06-03 13:55 ` Andrew Lunn @ 2009-06-03 14:19 ` Nikolay Marusov 0 siblings, 0 replies; 3+ messages in thread From: Nikolay Marusov @ 2009-06-03 14:19 UTC (permalink / raw) To: Nikolay Marusov, ecos-discuss 2009/6/3 Andrew Lunn <andrew@lunn.ch>: > On Wed, Jun 03, 2009 at 05:43:04PM +0400, Nikolay Marusov wrote: > > Is it an overrun or an underrun? > > I've seen underrun problems before in an intel chipset. The problem > was that the DMA would start transferring the packet from the host RAM > to the ethernet chipset. When X bytes of the packet had arrived at the > ethernet, the ethernet started sending them on the wire. Under heavy > memory load, the DMA was slower than the Ethernet sending bytes on the > wire, and with long packets the ethernet chip would empty its buffer > and then throw an underrun error. I had the change the Ethernet > chipset to have a bigger X so it had more buffered bytes before it > started sending them to the wire. > > Andrew > Yes, it is underrun - sorry. Exactly this case. So thought I. I was interested whether anybody has such a thing at EA2468. If this problem is insuperable, one could use this: In phy_eth_drivers.cdl: cdl_option CYGOPT_DEVS_ETH_PHY_SPEED { display "Preferred speed" flavor data legal_values 10 100 default_value 100 description "This option allows to select the preferred interface speed during auto-negitiation." } In dev/KSZ8001.c: #if CYGOPT_DEVS_ETH_PHY_SPEED == 10 _eth_phy_read(f, PHY_AN_ADV, f->phy_addr, &phy_anadv_reg); _eth_phy_write(f, PHY_AN_ADV, f->phy_addr, (phy_anadv_reg & ~PHY_AN_ADV_100HDX & ~PHY_AN_ADV_100FDX & ~PHY_AN_ADV_100_T4 )| PHY_AN_ADV_10HDX | PHY_AN_ADV_10FDX); #endif Thank you. Nikolay. -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2009-06-03 14:19 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2009-06-03 13:43 [ECOS] ea2468 Ethernet overrun Nikolay Marusov 2009-06-03 13:55 ` Andrew Lunn 2009-06-03 14:19 ` Nikolay Marusov
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