Messages in this thread | | | From | Alan Tull <> | Date | Wed, 20 Dec 2017 16:31:15 -0600 | Subject | Re: [PATCH v3 01/21] docs: fpga: add a document for Intel FPGA driver overview |
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On Mon, Nov 27, 2017 at 12:42 AM, Wu Hao <hao.wu@intel.com> wrote: > + > +PORT > +==== > +A port represents the interface between the static FPGA fabric (the "blue > +bitstream") and a partially reconfigurable region containing an AFU (the "green > +bitstream"). It controls the communication from SW to the accelerator and > +exposes features such as reset and debug.
Hi Hao,
If I remember correctly, reset means that the accelerator gets reset and this is something that is desirable to do between jobs. I've asked for some documentation about the port reset function, partly because the idea of being able to reset hardware from userspace somehow scares me. So please find a good logical place to explain what a port reset does and how it is safe for userspace to request it at some arbitrary time and how it won't crash the kernel. We discussed this in v2, I grepped v3 for it, maybe I missed it, but I don't see it in v3. My understanding is that disabling and reenabling the port bridge causes the accelerator in its FPGA region to get reset.
Alan
> + > +A PCIe device may have several ports and each port can be released from PF by > +FPGA_FME_PORT_RELEASE ioctl on FME, and exposed through a VF via PCIe sriov > +sysfs interface. > +
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