[PATCH v3 13/28] pci: Update to use new sequence numbers

Tim Harvey tharvey at gateworks.com
Tue Apr 13 20:32:15 CEST 2021

On Sat, Dec 19, 2020 at 8:43 AM Simon Glass <sjg at chromium.org> wrote:
> Now that we know the sequence number at bind time, there is no need for
> special-case code in dm_pci_hose_probe_bus().
> Note: the PCI_CAP_ID_EA code may need a look, but there are no test
> failures so I have left it as is.
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
> Changes in v3:
> - Update PCI to use manual sequence numbering
> Changes in v2:
> - Use the sequence number directly instead of max bus
>  drivers/pci/pci-uclass.c | 45 ++++++++++++++++++++++++----------------
>  drivers/pci/pci_auto.c   | 10 ++++-----
>  2 files changed, 32 insertions(+), 23 deletions(-)
> Applied to u-boot-dm/next, thanks!

Hi Simon,

I have a (not yet submitted) pending patch to migrate the gwventana
board to DM_PCI / DM_ETH that this particular patch broke and I'm
trying to understand why.

The Gateworks Ventana boards have a PCIe switch where the downstream
PERST#'s are GPIO's off the switch and a e1000 PCIe GBe device is on
one of those downstream ports. For non-dm PCI I have a
'board_pci_fixup_dev' function that allows board support to configure
the switch's GPIO and toggle downstream PERST# during enumeration.
When I add this function to dm_pci I end up getting a data abort when
the e1000 driver tries to initialize (after PCI enumeration).

Any idea what is causing this and what I need to do to work around it?
Nothing in my patch deals with device sequence numbers.

Additionally I feel like the best way to add support for the custom
downstream PCI switch reset requirements is to add a UCLASS_PCI driver
for the switch in my board support but when I attempted that solution
I run into an issue where pci read/write's cause a prefetch abort
because I need to use imx_pcie_dm_{read,write}_config instead of the
default ops. I'm not quite sure how to get hold of the ops for the imx
controller to set this up properly. Furthermore if I do end up with
that solution I later need to be able to walk the PCI bus to perform
various dt fixups on pci device nodes - do you have an example of how
I could walk the bus using DM_PCI?

Best regards,


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