How to make PCIe works on MPC8308?

[oska874]

I'm trying to using PCIe on mpc8308,and I have connectted 8308(works in RC mode ) to a PCIe device(FPGA implement a PCIe device works as EP mode).I configured PCIe configuration registers in cpu as the "MPC8308 Reference Manual 14.7.1 Initialization Sequence" said and the link is ok:PEX_LTSSM_STAT's status code is 16.(these code is mainly based on u-boot 's code under mpc8308rdb folder) But I failed when I try to use DMA descrptor send&receive data.Then I read the "PCI Express Slot Status Register",the bit PDS is 0 which means "slot empty".What's more,PEX_WDMA_STAT's value is 0x60 when I start  write DMA .

Now I'm stumble here, have no idea to what to do .Can anybody give me a hand?

ps:I have read the code in linux kernel and uboot,but found nothing

[ufedor]

Hello,

Please note that the descriptor uses little-endian byte ordering.

If the issue is still not resolved please create a Technical Service Request.

[oska874]

I've made descriptor in little-endian.

Now I may found the reason:mmu settings may have some errors,especially BATs.

I tried to compile a uboot with PCIe support.When I read the content of  CSB address that mapped to PCIe address,it returns the value of the opposite PCIe core, while I read failed on my own application.The only different between uboot and my application is the BATs settings:uboot used 4 BATs while I used 7 BATs.

[ufedor]

Please create a Technical Service Request for the new issue.

[Wlodek_D_]

Hello,

Thank you for your post, however please consider moving it to the right community place (e.g. PowerQUICC Processors ) to get it visible for active members.

For details please see general advice Where to post a Discussion?

Thank you for using Freescale Community.