Re: DPAA2 triggers, [PATCH] dma debug: report -EEXIST errors in add_dma_entry

From: Ioana Ciornei
Date: Thu Sep 09 2021 - 17:16:36 EST

On Wed, Sep 08, 2021 at 10:33:26PM -0500, Jeremy Linton wrote:
> +DPAA2, netdev maintainers
> Hi,
> On 5/18/21 7:54 AM, Hamza Mahfooz wrote:
> > Since, overlapping mappings are not supported by the DMA API we should
> > report an error if active_cacheline_insert returns -EEXIST.
> It seems this patch found a victim. I was trying to run iperf3 on a
> honeycomb (5.14.0, fedora 35) and the console is blasting this error message
> at 100% cpu. So, I changed it to a WARN_ONCE() to get the call trace, which
> is attached below.

Thanks for the report.

I don't have access to hardware at the moment to actually see what's
happening since I'm on vacation. I'll work on it in a few days.