Re: PCI resource collision message

From: Robert Hancock
Date: Wed Dec 31 2008 - 12:42:00 EST


yogeshwar sonawane wrote:
Hi Robert,

Currently card is inserted in PCI slot 06:00.0 & working fine. The
above said problem is observed very few times like 2 or 3. So, i am
sending today's lspci -vv output.
The lspci -vv output follows & it is attached also: -

(snip)


06:00.0 Network controller: Centre for Development of Advanced
Computing: Unknown device 0102
Subsystem: Centre for Development of Advanced Computing: Unknown device 0102
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
Stepping- SERR- FastB2B-
Status: Cap+ 66Mhz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
<TAbort- <MAbort- >SERR- <PERR-
Latency: 0, Cache Line Size 08
Interrupt: pin A routed to IRQ 114
Region 0: Memory at de000000 (64-bit, non-prefetchable) [size=16M]
Region 2: Memory at d8000000 (64-bit, prefetchable) [size=64M]
Region 4: Memory at dc000000 (64-bit, prefetchable) [size=32M]
Capabilities: [40] Power Management version 2
Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
Status: D0 PME-Enable- DSel=0 DScale=1 PME-
Capabilities: [48] Message Signalled Interrupts: 64bit+ Queue=0/0 Enable+
Address: 00000000fee02000 Data: 4072
Capabilities: [58] Express Endpoint IRQ 0
Device: Supported: MaxPayload 512 bytes, PhantFunc 0, ExtTag-
Device: Latency L0s unlimited, L1 unlimited
Device: AtnBtn- AtnInd- PwrInd-
Device: Errors: Correctable- Non-Fatal- Fatal- Unsupported-
Device: RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+
Device: MaxPayload 128 bytes, MaxReadReq 512 bytes
Link: Supported Speed 2.5Gb/s, Width x4, ASPM L0s, Port 0
Link: Latency L0s unlimited, L1 unlimited
Link: ASPM Disabled RCB 64 bytes CommClk- ExtSynch-
Link: Speed 2.5Gb/s, Width x4
Capabilities: [100] Device Serial Number 00-00-00-00-00-00-00-00

Well, everything seems pretty much fine here.. think we'd really need the lspci and dmesg output when the problem actually shows up. I'm not sure why the BIOS wouldn't have been able to allocate resources for the card only sometimes.. The only thing that seems unusual is that you don't often see devices with a 16MB non-prefetchable BAR (the big ones are usually prefetchable video RAM from a graphics card), and the non-prefetchable and prefetchable regions may have to go into different bridge windows.. it could be that is tripping up the BIOS.

On Wed, Dec 31, 2008 at 12:47 PM, Robert Hancock <hancockr@xxxxxxx> wrote:
yogeshwar sonawane wrote:
Hi all,

I have seen the following message in /var/log/messages file :-

PCI: Device 0000:01:00.0 not available because of resource collisions

Whenever this msg comes, the PCI card which is present in 0000:01:00.0
is not useful/accessible.
While detection of card, pci_set_master() fails.
But after reboot, that msg goes & card is working fine.

This card is a Network controller PCI-Express based card.
The above problem comes very rarely & not on all the test nodes. The
situation may be difficult to reproduce.

So, my question is, what to interpret from the above message ?
PCI bios allocates the PCI resources. So where to look to remove this
error ?
Is there something overlapping in the PCI resource allocations? Can you post
the lspci -vv output?

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