Re: Problem in reading cfg space of device connected below a bridge

Re: Problem in reading cfg space of device connected below a bridge

[Pratyush Anand]

Grant Grundler <grundler <at> parisc-linux.org> writes:

After a long time , I am back to this issue again. I have taken log from 
analyser, and I can see that my host controller is correctly generating cfgrd1.
What could be wrong?

This is text exported log of lecroy PCIe analyser.

Packet(951428) Downstream 2.5(x1) TLP(97) Cfg 
_______| CfgWr0(10:00100) Length(1) RequesterID(002:00:0) Tag(0) 
_______| DeviceID(003:00:0) Register(0x018) 1st BE(1111) 
_______| Secondary Latency Timer(0x00) Subordinate Bus Number(0xFF) 
_______| Secondary Bus Number(0x04) Primary Bus Number(0x03) LCRC(0x564084DF) 
_______| Time Stamp(0047 . 793 106 288 s) 
_______|_______________________________________________________________________
Filtered Traffic 
Packet(951429) Upstream 2.5(x1) TLP(96) Cpl Cpl(00:01010) 
_______| Length(0) RequesterID(002:00:0) Tag(0) CompleterID(003:00:0) Status
(SC) 
_______| BCM(0) Byte Cnt(4) Lwr Addr(0x00) LCRC(0x502279E4) 
_______| Time Stamp(0047 . 793 106 552 s) 
_______|_______________________________________________________________________
Filtered Traffic 
Packet(951430) Upstream 2.5(x1) DLLP ACK 
_______| AckNak_Seq_Num(97) CRC 16(0x1425) Time Stamp(0047 . 793 107 004 s) 
_______|_______________________________________________________________________
Packet(951431) Downstream 2.5(x1) DLLP ACK AckNak_Seq_Num(96) 
_______| CRC 16(0xB53E) Time Stamp(0047 . 793 108 056 s) 
_______|_______________________________________________________________________
Filtered Traffic 
Packet(951432) Downstream 2.5(x1) TLP(98) Cfg 
_______| CfgRd1(00:00101) Length(1) RequesterID(002:00:0) Tag(1) 
_______| DeviceID(004:00:0) Register(0x000) 1st BE(1111) LCRC(0xDFA187B4) 
_______| Time Stamp(0047 . 793 110 456 s) 
_______|_______________________________________________________________________
Filtered Traffic 
Packet(951433) Upstream 2.5(x1) TLP(97) Cpl Cpl(00:01010) 
_______| Length(0) RequesterID(002:00:0) Tag(1) CompleterID(004:00:0) 
_______| Status(UR)-BAD BCM(0) Byte Cnt(4) Lwr Addr(0x00) LCRC(0xBBC69D2D) 
_______| Time Stamp(0047 . 793 110 960 s) 
_______|_______________________________________________________________________
Packet(951434) Upstream 2.5(x1) DLLP ACK AckNak_Seq_Num(98) CRC 16(0xF709) 
_______| Time Stamp(0047 . 793 111 148 s) 
_______|_______________________________________________________________________
Packet(951435) Downstream 2.5(x1) DLLP ACK AckNak_Seq_Num(97) 
_______| CRC 16(0x1425) Time Stamp(0047 . 793 112 488 s) 
_______|______________________________________________________________________


regards
Pratyush

Re: Problem in reading cfg space of device connected below a bridge

[Pratyush Anand]

Well, today I got some conclusive observation.
Actually, the bridge which I connect does not have a device with
device number 0.
It has first device with device number 4.
So, I hardcoded in my linux code and sent a CFGRD1 with bus 2, dev 4,
and func 0. I was able to access its configuration space.
But my software aborts if I send request with bus 2, dev 0 and func 0.

Now my question is, is it the responsibilty of PCIe RC controller to
return 0xFFFF as VID if it receives an UR (unsupported request from
downstream device)
or,
is it the responsibilty of software to implement an appropriate abort
handler in this case?

Regards
Pratyush

On Fri, Dec 9, 2011 at 7:09 PM, Pratyush Anand <pratyush.anand@gmail.com> wrote:
> Grant Grundler <grundler <at> parisc-linux.org> writes:
>
> After a long time , I am back to this issue again. I have taken log from
> analyser, and I can see that my host controller is correctly generating cfgrd1.
> What could be wrong?
>
> This is text exported log of lecroy PCIe analyser.
>
> Packet(951428) Downstream 2.5(x1) TLP(97) Cfg
> _______| CfgWr0(10:00100) Length(1) RequesterID(002:00:0) Tag(0)
> _______| DeviceID(003:00:0) Register(0x018) 1st BE(1111)
> _______| Secondary Latency Timer(0x00) Subordinate Bus Number(0xFF)
> _______| Secondary Bus Number(0x04) Primary Bus Number(0x03) LCRC(0x564084DF)
> _______| Time Stamp(0047 . 793 106 288 s)
> _______|_______________________________________________________________________
> Filtered Traffic
> Packet(951429) Upstream 2.5(x1) TLP(96) Cpl Cpl(00:01010)
> _______| Length(0) RequesterID(002:00:0) Tag(0) CompleterID(003:00:0) Status
> (SC)
> _______| BCM(0) Byte Cnt(4) Lwr Addr(0x00) LCRC(0x502279E4)
> _______| Time Stamp(0047 . 793 106 552 s)
> _______|_______________________________________________________________________
> Filtered Traffic
> Packet(951430) Upstream 2.5(x1) DLLP ACK
> _______| AckNak_Seq_Num(97) CRC 16(0x1425) Time Stamp(0047 . 793 107 004 s)
> _______|_______________________________________________________________________
> Packet(951431) Downstream 2.5(x1) DLLP ACK AckNak_Seq_Num(96)
> _______| CRC 16(0xB53E) Time Stamp(0047 . 793 108 056 s)
> _______|_______________________________________________________________________
> Filtered Traffic
> Packet(951432) Downstream 2.5(x1) TLP(98) Cfg
> _______| CfgRd1(00:00101) Length(1) RequesterID(002:00:0) Tag(1)
> _______| DeviceID(004:00:0) Register(0x000) 1st BE(1111) LCRC(0xDFA187B4)
> _______| Time Stamp(0047 . 793 110 456 s)
> _______|_______________________________________________________________________
> Filtered Traffic
> Packet(951433) Upstream 2.5(x1) TLP(97) Cpl Cpl(00:01010)
> _______| Length(0) RequesterID(002:00:0) Tag(1) CompleterID(004:00:0)
> _______| Status(UR)-BAD BCM(0) Byte Cnt(4) Lwr Addr(0x00) LCRC(0xBBC69D2D)
> _______| Time Stamp(0047 . 793 110 960 s)
> _______|_______________________________________________________________________
> Packet(951434) Upstream 2.5(x1) DLLP ACK AckNak_Seq_Num(98) CRC 16(0xF709)
> _______| Time Stamp(0047 . 793 111 148 s)
> _______|_______________________________________________________________________
> Packet(951435) Downstream 2.5(x1) DLLP ACK AckNak_Seq_Num(97)
> _______| CRC 16(0x1425) Time Stamp(0047 . 793 112 488 s)
> _______|______________________________________________________________________
>
>
> regards
> Pratyush
>
> --
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