[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] tg3 NIC driver bug in 3.14.x under Xen [and 3 more messages]




On 4/15/2015 3:54 AM, Ian Jackson wrote:
Prashant writes ("Re: tg3 NIC driver bug in 3.14.x under Xen [and 3 more 
messages]"):
I tried to reproduce the problem on 32 bit 3.14.34 stable kernel
baremetal, with iommu=soft swiotlb=force but no luck, no drops or
errors. I did not try with Xen 64 bit yet. Btw I need a pcie analyzer
trace to confirm the problem. Is it feasible to capture at your end ?

In private correspondence with Prashant we have established that
Prashant was using a different kernel configuration.  Prashant
provided me with their kernel and module binaries, which work in my
environment.

I have also established that I can reproduce the problem with 3.14.37
(`iommu=soft swiotlb=force' baremetal => all rx wholly corrupted).

The kernel config I was using is here:
   
http://logs.test-lab.xenproject.org/osstest/logs/50387/build-i386-pvops/build/config

As far as I am aware no-one at Broadcom has attempted a build and test
using my kernel config.


Ian, using your config we are able to recreate the problem that you are seeing. The driver finds the RX data buffer to be all zero, with a analyzer trace we are seeing the chip is DMA'ing valid RX data buffer contents to the host but once the driver tries to read this DMA area, it is seeing all zero's which is the reason of the corruption. This is only for the RX data buffer, the RX descriptor and status block update DMA regions are having valid contents.

This is unlikely to be a chip or driver issue, as the chip is doing the correct DMA but the corruption occurs before driver reads it. Would request iommu experts to take a look and suggest what can be done next.

We are more than willing to try any changes in the driver, I have added few more team members who will work with you if needed. Thanks.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.