AM5728: Simultaneous use of both PCIe ports

The PCIe experts have been notified. They will respond here.

Hi Rex

Thanks a lot for the information. Before making the hardware, I want to run some tests on EVM. I had Pericom PCIe switch and bridge cards in the neighborhood. 

I plugged a Pericom PCIe x1 to 3 x1 switch card with PI7C9X2G404SL chip into EVM but the OS did not detect it. I also plugged a Pericom PCIe x1 to PCI bridge card with PI7C9X111SL chip into EVM but the OS did not detect it either.

I have tested the PCIe module of the EVM with 2 different WiFi cards and it seems the PCIe bus is live and active. But I could not get any response from switch nor bridge. 

I also plugged an ASIX MCS9901 miniPCIe to UART card into EVM but there was no response.

All the cards I have mentioned are functional in the PC.

I have checked the schematics of EVM. It seems it just uses the PERSTn signal and there is no WAKEn nor CLKREQn. And there is just PERSTn entry on the dts file. Is this going to make any problems with PCIe peripheral modules?

Thanks for your help

Hi Again

Just an update: We could communicate with PI7C9X111SL PCIe to PCI bridge chip and the peripheral cards attached to it. The problem was from the power connector. We are trying to get answers from the other modules but nothing comes out.

Thanks

Aldin,
Please let us know if you got all working....thanks for using our AM57x.

Hi Rogerio

I have successfully connect the PCIe to PCI bridge and I used 2 different PCI cards. They were successfully identified and I could communicate with them without any problems.

But I could not interface the PCIe switch to the AM5728. The PCIe switch was not identified by the Linux and I could not figure it out yet.

Any suggestions?

Thanks.

Hi Rex
We are aware about the driver installation. We have compiled the driver for the AM5728 and we checked it (#insmod) is running on target. The problem is, the ASIX End Point device is not even detected on PCIe bus. The output of lspci command is not showing it. But even if the driver is not installed, the output of lspci command should show the device. For example I use an Intel Wi-Fi 5100 card and it was detected by lspci (the driver of the card is not available for ARM platform and Intel just provided a ucode for x86 and x64 platforms).
I suspect there is something with control signals that the ASIX use, Since the AM5728 PCIe just provide the PERST# and there is no support for other signals like WAKE# & CLKREQ# .

Any suggestions ?
Thanks a lot.

Hi, Aidin,

We don't have experience with this ASIX device, but I downloaded its linux driver and took a look at the package. Did you follow the steps in the readme to cross-compile the module and rebuild the kernel? This is the only thing I can think of.
I am not familiar with hardware signals to tell if they are significant, but if they were, wouldn't it cause compatibility with other end devices, not just ASIX?

Rex

Hi, Aidin,

I just checked with Hardware engineer about the WAKE# and CLKREQ# signals and is it possible the cause for the device not detected, and his response is:

They would need to strap those pins according to the ASIX data manual. I’m not familiar with that device so I couldn’t say if they will keep it from being recognized (but I doubt it).

Rex

Hi Rex

Yes the procedure for cross compiling the module was done correctly. But regardless of the module being in the kernel or not, the PCIe EP should be detected. My main problem is the device is not detected on the link.
The PCIe switch is not detected either.
I checked the PCIe specs again, it is just the PERST# signal needed from RC to EP and WAKE# & CLKREQ# are not mandatory since they are output from EP.
I try to figure it out. Maybe I change the device and let you know here.