Re: [lwip-users] pbuf_alloc failed after sometime at driver side.

[Vincent Cui]

This is LPC driver issue ...

Vincent



Vincent Cui
Firmware Engineer Leader
Shanghai Enlogic Electric Technology Co., Ltd.
Room1106, Building A, New Caohejing Business Centre, No.391, Guiping Road, 
Xuhui District, Shanghai, P.R.China
T: +86 21 34612525, M: +86 13482482211
www.enlogic.com
------------------------------------------------------------------------
Please consider the environment before printing this email.
------------------------------------------------------------------------

This email and any files transmitted with it are confidential and intended 
solely for the use of the individual or entity to which they are addressed.  If 
you have received this e-mail in error, please notify the sender immediately 
and then delete it.  If you are not the intended recipient, you must not use, 
disclose or distribute this e-mail without the author's prior permission. We 
have taken precautions to minimize the risk of transmitting software viruses, 
but we advise you to carry out your own virus checks on any attachment to this 
message.  We cannot accept liability for any loss or damage caused by software 
viruses.  Any views and/or opinions expressed in this e-mail are of the author 
only and do not necessarily represent the views of Enlogic.
------------------------------------------------------------------------
-----Original Message-----
From: address@hidden [mailto:address@hidden On Behalf Of Slava Zilberfayn
Sent: 2014年10月16日 10:34
To: Mailing list for lwIP users
Subject: Re: [lwip-users] pbuf_alloc failed after sometime at driver side.

Hello Slava,

Hm, the driver was missing error handling, naturally the missing packets 
returned some error. Looking further...

Regards, Slava

Wednesday, October 15, 2014, 3:54:16 PM, you wrote:

SZ> Hello,

SZ> I'm having some issues with lwip stack, or rather with the system as
SZ> whole. At this point I studied the stack relatively well at seems to
SZ> work as intended. However I might be still mistaken, so I'm posting
SZ> here.

SZ> The root of the problems is that sometimes packets are being lost
SZ> for no reason. This can happen even if I connect my PC directly to
SZ> the lwip device.

SZ> When I look at the WireShark trace, it shows as "TCP Previous
SZ> Segment not captured". See attachment. It is certainly not just "not
SZ> captured", as this is always accompanied by problems on receiving
SZ> end and netconn_write takes longer time to be completed. Eventually
SZ> the packets are retransmitted, but it could take like 10 seconds,
SZ> which is not very good.

SZ> I already instrumented the driver (lpc17_emac), and logs confirm
SZ> that all packets are leaving my device strictly in order. What could
SZ> be the reason for router to ignore my packets? I also tried with two
SZ> different routers and it is the same. Could the problem be with MAC-PHY 
link?

SZ> Can anybody suggest further steps for debugging?

SZ> Thanks, Slava

--
Slava Zilberfayn mailto:address@hidden
Phone: 416 7289367

Home Electronics, www.home-electro.com
100 Drumlin Circle,
Suite 205
Concord, ON, L4K 3E6
CANADA



_______________________________________________
lwip-users mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/lwip-users