From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: Felix Kuhlmann <felix-kuhlmann@gmx.de>
Cc: linux-remoteproc@vger.kernel.org
Subject: Re: Question regarding optimisation of RPMsg round trip times on Xilinx ZynqMP hardware
Date: Mon, 28 Oct 2024 09:17:07 -0600 [thread overview]
Message-ID: <CANLsYkyq5Ge4-RZEPDsvMgqtzL10XonVMdHJOGAbcHyXHWV_Cg@mail.gmail.com> (raw)
In-Reply-To: <ZxzLHcWpjeo9sJGN@fedora>
Hi Felix,
On Sat, 26 Oct 2024 at 04:57, Felix Kuhlmann <felix-kuhlmann@gmx.de> wrote:
>
> Hello everybody,
>
> I need your help concerning an error that was returned while trying to
> use the AMD Xilinx implementation of remoteproc. I hope that this is
> the right place to ask for help.
>
> I'm currently working on a project that requires Remoteproc and
> RPMsg. The hardware I am working with is a Trenz SoM containing a
> AMD Zynq UltraScale+ MPSoC, CG variant, DDR3 external RAM and a few
> additional components.
>
> One of the targets of the project is that the communication between
> the RPU and the APU should happen under soft realtime conditions. The
> issue with the communication examples provided by Xilinx is that they
> use the external RAM for the buffers for RPMsg. This results in highly
> non-deterministic communication delay jitter, which is most likely due
> to the fact that DDR RAM is not suited for those applications.
>
> Given that the SoC already has an On-Chip Memory that is designed for such
> applications, I am curious whether changing the shared memory location
> for RPMsg to reside inside of the OCM of the SoC result in a performance
> boost. Do you have any experience with such performance benefits?
>
I do not have direct experience with this kind of configuration but I
would think both vring and vdev buffers would need to be located on
the OCM. That said the OCM may not be big enough for that or it may
not be accessible by the main processor. Another option could be to
use non-cached device memory, but there may also be constraints at
that level as well. This is really HW specifics and I do not have
enough details to provide further guidance.
Thanks,
Mathieu
> I'm currently developing a solution, trying to adopt the examples AMD
> provides, but when trying to boot the fw image, Remoteproc complains that
> it is unable to allocate the memory, saying the fw image size doesn't
> fit the len request. This results in Remoteproc throwing error "-12",
> which simply indicates that booting of the RPU failed. More information
> isn't logged.
>
> I have tried to read the documentation, but I can't really decide which
> aspects I need to bear in mind when trying to adopt my code to use a
> different memory region as a whole.
>
> My previous attempts at circumventing this issue failed, resulting in
> the error above.
> A few of the things I've tried are:
> - Changing the shared memory and the vring addresses to be inside of
> the OCM
> - Adding the OCM and the remoteproc buffers to the device tree
> - Attempting to increase the requested carveout for the firmware
>
> I hope this provides a sufficient overview of my situation. If you need
> further information or logs in order to figure out what went wrong,
> feel free to ask for that.
>
> Thank you in advance and best regards,
>
> Felix Kuhlmann
>
>
prev parent reply other threads:[~2024-10-28 15:17 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-26 10:57 Question regarding optimisation of RPMsg round trip times on Xilinx ZynqMP hardware Felix Kuhlmann
2024-10-28 15:17 ` Mathieu Poirier [this message]
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