Intel DP43BF requires "pci=assign-busses" to discover some devices
A message that is not in the archive (sent off-list or not yet received): [email protected]/
A message that is not in the archive (sent off-list or not yet received): [email protected]
Bjorn Helgaas
maintainerQuoted 8 lines · On Fri, Sep 7, 2012 at 2:40 PM, <[email protected]> wrote:
https://bugzilla.kernel.org/show_bug.cgi?id=18412
--- Comment #4 from VL <[email protected]> 2012-09-07 21:40:04 --- The bug is still there with behaviour exactly as specified by reporter.
Tested with linux-3.4.9 (gentoo), DP43BF motherboard and Intel PRO/1000 NICs. With pci=assign-busses lspci shows devices properly, without it nothing is in the list.
Anybody who wants to help with bugs like this, feel free :) There are a number of open regressions and bugs in the PCI subsystem of
https://bugzilla.kernel.org/
I spend a lot of time looking at these bugs, and that reduces the time I have to review and apply patches.
Quoted 9 lines · Bjorn Helgaas
Quoted 8 lines · On Fri, Sep 7, 2012 at 2:40 PM, <[email protected]> wrote:
https://bugzilla.kernel.org/show_bug.cgi?id=18412
--- Comment #4 from VL <[email protected]> 2012-09-07 21:40:04 --- The bug is still there with behaviour exactly as specified by reporter.
Tested with linux-3.4.9 (gentoo), DP43BF motherboard and Intel PRO/1000 NICs. With pci=assign-busses lspci shows devices properly, without it nothing is in the list.
VL,
I rebased for-pci-busn-alloc branch to current pci-next
please check if could fix the problem.
git://git.kernel.org/pub/scm/linux/kernel/git/yinghai/linux-yinghai.git
for-pci-busn-alloc
Thanks
Yinghai
Quoted 13 lines · Yinghai Lu
Quoted 9 lines · Bjorn Helgaas
Quoted 8 lines · On Fri, Sep 7, 2012 at 2:40 PM, <[email protected]> wrote:
https://bugzilla.kernel.org/show_bug.cgi?id=18412
--- Comment #4 from VL <[email protected]> 2012-09-07 21:40:04 --- The bug is still there with behaviour exactly as specified by reporter.
Tested with linux-3.4.9 (gentoo), DP43BF motherboard and Intel PRO/1000 NICs. With pci=assign-busses lspci shows devices properly, without it nothing is in the list.
VL,
Quoted 9 lines
I rebased for-pci-busn-alloc branch to current pci-next
please check if could fix the problem.
git://git.kernel.org/pub/scm/linux/kernel/git/yinghai/linux-yinghai.git
for-pci-busn-alloc
also you could try attached patch
Thanks
Yinghai
drivers/pci/probe.c +2 -1
@@ -729,7 +729,8 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,/* Check if setup is sensible at all */ if (!pass && - (primary != bus->number || secondary <= bus->number)) { + (primary != bus->number || secondary <= bus->number || + secondary > subordinate )) {dev_dbg (&dev->dev,"bus configuration invalid, reconfiguring\n" ); broken =1 ; }
A message that is not in the archive (sent off-list or not yet received): [email protected]
Bjorn Helgaas
maintainerQuoted 8 lines · On Sun, Sep 9, 2012 at 2:27 AM, <[email protected]> wrote:
https://bugzilla.kernel.org/show_bug.cgi?id=18412
--- Comment #14 from VL <[email protected]> 2012-09-09 08:27:17 ---
Quoted 3 lines
Given the [bus 20-08] range, I suspect that the patch in comment #9 may fix it, and that's something we could apply. Can you try just that patch on top of a 3.5 or 3.6-rc4 kernel?
yes, this patch fixes the problem.
Yinghai, you put the following (whitespace damaged) patch in the bugzilla, and VL says it fixes his sytem. He has a P2P bridge with secondary > subordinate:
pci 0000:00:1e.0: PCI bridge to [bus 20-08] (subtractive decode)
The current kernel doesn't probe behind this bridge, so it doesn't find a couple devices. With the patch below, we reassign the secondary bus number from 20 to 08, so we do find those devices.
I'm slightly concerned that if we apply a patch like this, it removes one way a BIOS could hide devices from the OS. But maybe we don't need to worry about that. We have to configure hot-added P2P bridges from scratch, so maybe we should be aggressive about fixing bridges like this, too.
Are you comfortable enough with this patch to post it with a Signed-off-by?
drivers/pci/probe.c +0 -0
@@ -729,7 +729,8 @@ int __devinit pci_scan_bridge(struct pci_bus *bus,
struct pci_dev *dev, int max,
/* Check if setup is sensible at all */
if (!pass &&
- (primary != bus->number || secondary <= bus->number)) {
+ (primary != bus->number || secondary <= bus->number ||+ secondary > subordinate)) {
dev_dbg(&dev->dev, "bus configuration invalid, reconfiguring\n"); broken = 1;
}