* About use case of cdns3-pci-wrap.c
@ 2021-03-27 4:50 Peter Chen
2021-03-30 3:57 ` Pawel Laszczak
0 siblings, 1 reply; 2+ messages in thread
From: Peter Chen @ 2021-03-27 4:50 UTC (permalink / raw)
To: Pawel Laszczak; +Cc: linux-usb
Hi Pawel,
From the code of this file, it seems the controller driver is running at
PC side, but the hardware controller is at verification board, the two sides
are connected by PCIe. Am I right?
If I am right, the memory (eg, the TRB ring address and data buffer) the hardware
try to visit is at PC side, but how controller visits PC memory since the TRB ring
address is allocated dynamically by controller device driver running at
PC? How the local bus arbiter knows it is PCIe address at verification board?
Besides, could the upstream code run this IP verification solution through PCIe
without changing any code?
Thanks.
--
Thanks,
Peter Chen
^ permalink raw reply [flat|nested] 2+ messages in thread
* RE: About use case of cdns3-pci-wrap.c
2021-03-27 4:50 About use case of cdns3-pci-wrap.c Peter Chen
@ 2021-03-30 3:57 ` Pawel Laszczak
0 siblings, 0 replies; 2+ messages in thread
From: Pawel Laszczak @ 2021-03-30 3:57 UTC (permalink / raw)
To: Peter Chen; +Cc: linux-usb@vger.kernel.org
Hi Peter,
>
>Hi Pawel,
>
>From the code of this file, it seems the controller driver is running at
>PC side, but the hardware controller is at verification board, the two sides
>are connected by PCIe. Am I right?
>
>If I am right, the memory (eg, the TRB ring address and data buffer) the hardware
>try to visit is at PC side, but how controller visits PC memory since the TRB ring
>address is allocated dynamically by controller device driver running at
>PC? How the local bus arbiter knows it is PCIe address at verification board?
>Besides, could the upstream code run this IP verification solution through PCIe
>without changing any code?
Yes, the two sides, verification board and PC are connected by PCIe cable connected by using special PCIe
adapters.
The PC sees FPGA board as the part of PC hardware. It's work in the same way as standard XHCI controller
based on PCIe.
>
>Thanks.
>
>--
>
>Thanks,
>Peter Chen
Regards,
Pawel Laszczak
^ permalink raw reply [flat|nested] 2+ messages in thread
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2021-03-27 4:50 About use case of cdns3-pci-wrap.c Peter Chen
2021-03-30 3:57 ` Pawel Laszczak
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