Messages in this thread | | | From | Ohad Ben-Cohen <> | Date | Sun, 1 Apr 2012 09:15:55 +0300 | Subject | Re: Using remoteproc with ST-Ericsson modem. |
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Hi Sjur,
On Sun, Apr 1, 2012 at 12:25 AM, Sjur Brændeland <sjurbren@gmail.com> wrote: > Good stuff. One question from top of my mind: Have you considered > option of using rpmsg without the protocol, eg something like > RPMSG_RAW, where I can take advantage of rpmsg transport features > without needing the muxing feature. Then I could use CAIF muxing layer > without the rpmsg protocol and naming services....?
I think you may already be able to do so: the naming services are only enabled when VIRTIO_RPMSG_F_NS is present. About the rest of the rpmsg protocol - I think you can largely ignore it. Rpmsg drivers shouldn't really care about it, they just need to use the send/receive API and everything would just work.
> Another option is using virtio_console, but I realise virtio_console is doing > normal kmalloc so memory handling in virtio_console would have to change > then. (I have a memory addressing issue, so modem cannot access all > kernel memory).
What's the limitation you have? only a certain range of addresses is visible to the modem?
OMAP4 has a related problem: the memory that virtio_console allocates isn't immediately visible to the OMAP4's remote processors, because it isn't mapped in the relevant IOMMU. To fix this, we may need virtio_console to start allocating its memory with the DMA API (but we'll only start discussing it when the IOMMU-based DMA API will be merged). I guess that something along these lines would work out for you too ?
Thanks, Ohad. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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