From: "Marek Behún" <email@example.com>
To: Bjorn Helgaas <firstname.lastname@example.org>
Cc: "Pali Rohár" <email@example.com>,
"Stefan Chulski" <firstname.lastname@example.org>,
"Bjorn Helgaas" <email@example.com>,
"Thomas Petazzoni" <firstname.lastname@example.org>,
"Stefan Roese" <email@example.com>, "Phil Sutter" <firstname.lastname@example.org>,
"Mario Six" <email@example.com>,
"Lorenzo Pieralisi" <firstname.lastname@example.org>,
Subject: Re: [EXT] Re: pci mvebu issue (memory controller)
Date: Wed, 2 Jun 2021 23:59:36 +0200 [thread overview]
Message-ID: <20210602235936.4dac5537@thinkpad> (raw)
On Wed, 2 Jun 2021 23:13:35 +0200
Pali Rohár <email@example.com> wrote:
> > If the NICs are ordinary PCIe endpoints there must be *something* to
> > terminate the other end of the link. Maybe it has some sort of
> > non-standard programming interface, but from a PCIe topology point of
> > view, it's a root port.
> > I don't think I can contribute anything to the stuff below. It sounds
> > like there's some confusion about how to handle these root ports that
> > aren't exactly root ports. That's really up to uboot and the mvebu
> > driver to figure out.
> Yes, I understand, it is non-standard and since beginning I'm also
> confused how this stuff work at all... And this is also reason why
> kernel emulates those root ports (via virtual PCIe bridge devices) to
> present "standard" topology.
> Remaining question is: should really kernel filter that "memory
> controller" device and do not show it in linux PCIe device hierarchy?
this discussion has gone a little too complex.
The basic issue which Pali tries to solve can be recapitulated:
- there is a "memory controller" device on the "virtual" bus
- Linux' pci-mvebu driver hides this device
- we don't know what is the purpose of this device; it is visible even
if there is no PCIe device connected
- Pali wants to know what is the purpose of this "memory controller"
and whether this device should be hidden by Linux and U-Boot, as it
currently is, or if the controller driver should expose this device
next prev parent reply other threads:[~2021-06-02 21:59 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210602110703.ymdt6nxsjl7e6glk@pali>
2021-06-02 19:14 ` [EXT] Re: pci mvebu issue (memory controller) Bjorn Helgaas
2021-06-02 20:39 ` Pali Rohár
2021-06-02 21:01 ` Bjorn Helgaas
2021-06-02 21:13 ` Pali Rohár
2021-06-02 21:59 ` Marek Behún [this message]
2021-02-09 13:17 Marek Behún
2021-02-10 8:54 ` Thomas Petazzoni
2021-02-10 13:59 ` [EXT] " Stefan Chulski
2021-02-19 17:44 ` Pali Rohár
2021-03-04 18:29 ` Bjorn Helgaas
2021-11-01 18:07 ` Jason Gunthorpe
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