pci_read_config8 > 100 bytes crashes pci-bios

QNX Newsgroups (Archives) qdn.public.qnxrtp.os
1

The title kind of says it all. I tried to read the entire 255 byte
pci config space for a device in a single call to pci_read_config8,
and pci-bios crashed. Reading in segments of 20 bytes works fine.

Released Patch A.

Cheers,
Andrew

2

The pci_read_config() documents I saw said you must read < 100 bytes at
a time. See the Returns section of pci_read_config8(), where it returns
the PCI_BUFFER_TOO_SMALL error. That return means count is > 100 bytes.

I tried this some time ago, and it failed, but did not crask, in the old
QRTP version. I’ll try again.

Andrew Thomas wrote:

The title kind of says it all. I tried to read the entire 255 byte
pci config space for a device in a single call to pci_read_config8,
and pci-bios crashed. Reading in segments of 20 bytes works fine.

Released Patch A.

Cheers,
Andrew

–

John H. Zouck
The Johns Hopkins University
Applied Physics Laboratory

3

Previously, John H. Zouck wrote in qdn.public.qnxrtp.os:

The pci_read_config() documents I saw said you must read < 100 bytes
at a time. See the Returns section of pci_read_config8(), where it
returns the PCI_BUFFER_TOO_SMALL error. That return means count is
100 bytes.

Yes, I saw that. I was just surprised that pci-bios crashes instead
of returning PCI_BUFFER_TOO_SMALL.

Regards,
Andrew

4

Hi Andrew,

This has been fixed in the latest pci-bios, which may or may not make
it into the next release.



Andrew Thomas <Andrew@cogent.ca> wrote:

The title kind of says it all. I tried to read the entire 255 byte
pci config space for a device in a single call to pci_read_config8,
and pci-bios crashed. Reading in segments of 20 bytes works fine.

Released Patch A.

Cheers,
Andrew