RE: 82571EB: Detected Hardware Unit Hang

-----Original Message-----
From: Joe Jin [mailto:joe.jin@oracle.com]
Sent: Thursday, July 12, 2012 9:34 PM
To: Dave, Tushar N
Cc: e1000-devel@lists.sf.net; netdev@vger.kernel.org; linux-
kernel@vger.kernel.org
Subject: Re: 82571EB: Detected Hardware Unit Hang

On 07/13/12 12:10, Dave, Tushar N wrote:

quoted

quoted

-----Original Message-----
From: Joe Jin [mailto:joe.jin@oracle.com]
Sent: Thursday, July 12, 2012 4:46 PM
To: Dave, Tushar N
Cc: e1000-devel@lists.sf.net; netdev@vger.kernel.org; linux-
kernel@vger.kernel.org
Subject: Re: 82571EB: Detected Hardware Unit Hang

Thanks for sending full dmesg log. I am still investigating. I think

this issue can occur if two PCIe link partner *i.e pcie bridge and pcie
device do not have same max payload size.

quoted

I need 2 more info.
1) PBA number of the card.

This is a remote server and I could not get this.

quoted

2) full lspci -vvv output of entire system 'after you have changed max

payload size to 128'.

Somehow setting max payload to 256 from BIOS does not set this value for all devices. I believe this is a BIOS bug.
All devices in path from root complex to 82571, should have same max payload size otherwise it can cause hang. When you set max payload to 128 from BIOS, all device in path from root complex to 82571 got assigned same max payload size. This resolves the issue.

I hope this helps.

-Tushar