T-Series中的主题 Re: Dma over PCI device (device tree)

Dma over PCI device (device tree)

manoloruiz — Wed, 18 May 2016 15:35:06 GMT

Hi,

I want to do dma transfers between PCi device and RAM in my T2080RDB. I have created a device driver but it does not work properly. It looks like it is not allow to write in the address that I give to it .

I am wondering if I have to change something in the dbt or in the PCI configuration registers in my T2080rdb.

Any idea?

BR.

Re: Dma over PCI device (device tree)

lunminliang — Tue, 24 May 2016 02:37:32 GMT

Hello,

Could you please provide more information:

1. What version of Linux kernel using? SDK version?

2. What device driver trying to create?

3. What address trying to access?

4. Are you trying to access that address from user space or kernel space?

Thanks.

Lunmin

Re: Dma over PCI device (device tree)

manoloruiz — Tue, 24 May 2016 06:41:49 GMT

Hi Lunmin,

Thank very much for your answer. I have solved the problem. I used pci_set_dma_mask function in order to provide an address below 2GB. My PCI device only is able to acces the first 2 GB.

Best Regards