From: Mason <slash.tmp@free.fr>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: linux-pci <linux-pci@vger.kernel.org>,
Rob Herring <robh@kernel.org>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Thibaud Cornic <thibaud_cornic@sigmadesigns.com>,
David Laight <david.laight@aculab.com>,
Phuong Nguyen <phuong_nguyen@sigmadesigns.com>,
Shawn Lin <shawn.lin@rock-chips.com>,
Robin Murphy <robin.murphy@arm.com>,
Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: Neophyte questions about PCIe
Date: Tue, 14 Mar 2017 16:54:00 +0100 [thread overview]
Message-ID: <912c26d5-835f-9f39-73ba-db561b5bcffa@free.fr> (raw)
In-Reply-To: <94b3c89c-b116-288f-7530-15cc2611f425@free.fr>
On 14/03/2017 15:00, Mason wrote:
> On 10/03/2017 18:49, Mason wrote:
>
>> /* Root complex reports incorrect device class */
>> static void tango_pcie_fixup_class(struct pci_dev *dev)
>> {
>> dev->class = PCI_CLASS_BRIDGE_PCI << 8;
>> }
>
> Gen1 controller reports class/rev = 0x04800001
> Gen2 controller reports class/rev = 0x06000001
>
> #define PCI_CLASS_BRIDGE_HOST 0x0600
> #define PCI_CLASS_BRIDGE_ISA 0x0601
> #define PCI_CLASS_BRIDGE_EISA 0x0602
> #define PCI_CLASS_BRIDGE_MC 0x0603
> #define PCI_CLASS_BRIDGE_PCI 0x0604
> #define PCI_CLASS_BRIDGE_PCMCIA 0x0605
> #define PCI_CLASS_BRIDGE_NUBUS 0x0606
> #define PCI_CLASS_BRIDGE_CARDBUS 0x0607
> #define PCI_CLASS_BRIDGE_RACEWAY 0x0608
> #define PCI_CLASS_BRIDGE_OTHER 0x0680
>
> My fixup replaces 0x048000 with 0x060400.
>
> 0x060400 != 0x060000
>
> Which is correct:
> PCI_CLASS_BRIDGE_HOST or PCI_CLASS_BRIDGE_PCI?
>
> Naively, I would expect Host/PCI bridge to be more correct
> for a root complex.
But that's very likely wrong, since the code in Linux does:
switch (dev->hdr_type) { /* header type */
case PCI_HEADER_TYPE_BRIDGE: /* bridge header */
if (class != PCI_CLASS_BRIDGE_PCI)
goto bad;
/* The PCI-to-PCI bridge spec requires that subtractive
decoding (i.e. transparent) bridge must have programming
interface code of 0x01. */
So a class of PCI_CLASS_BRIDGE_HOST would error out, I think.
Does this mean I need to fixup Gen2 as well?
(Since it reports 0x060000)
Regards.
next prev parent reply other threads:[~2017-03-14 15:54 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-07 22:45 Neophyte questions about PCIe Mason
2017-03-08 13:39 ` Mason
2017-03-08 13:54 ` David Laight
2017-03-08 14:17 ` Mason
2017-03-08 14:38 ` David Laight
2017-03-09 22:01 ` Jeremy Linton
2017-03-08 15:17 ` Bjorn Helgaas
2017-03-09 23:43 ` Mason
2017-03-10 13:15 ` Robin Murphy
2017-03-10 14:06 ` David Laight
2017-03-10 15:05 ` Mason
2017-03-10 15:14 ` David Laight
2017-03-10 15:33 ` Mason
2017-03-10 15:23 ` Robin Murphy
2017-03-10 15:35 ` David Laight
2017-03-10 16:00 ` Robin Murphy
2017-03-13 10:59 ` Mason
2017-03-13 11:56 ` Robin Murphy
2017-03-10 18:49 ` Bjorn Helgaas
2017-03-10 14:53 ` Mason
2017-03-10 16:45 ` Mason
2017-03-10 17:49 ` Mason
2017-03-11 10:57 ` Mason
2017-03-13 21:40 ` Bjorn Helgaas
2017-03-13 21:57 ` Mason
2017-03-13 22:46 ` Bjorn Helgaas
2017-03-14 10:23 ` David Laight
2017-03-14 12:05 ` Mason
2017-03-14 12:24 ` David Laight
2017-03-13 14:25 ` Mason
2017-03-14 14:00 ` Mason
2017-03-14 15:54 ` Mason [this message]
2017-03-14 21:46 ` Bjorn Helgaas
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=912c26d5-835f-9f39-73ba-db561b5bcffa@free.fr \
--to=slash.tmp@free.fr \
--cc=ard.biesheuvel@linaro.org \
--cc=david.laight@aculab.com \
--cc=helgaas@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-pci@vger.kernel.org \
--cc=phuong_nguyen@sigmadesigns.com \
--cc=robh@kernel.org \
--cc=robin.murphy@arm.com \
--cc=shawn.lin@rock-chips.com \
--cc=thibaud_cornic@sigmadesigns.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).