Forum Discussion
Occasional ContributorIssues when testing DMA feature provided by Avalon MM+ IP with S10 GX dev kit card on Ubuntu 18.04
The problem you seen might related to below KBD
Why does the Intel® Stratix® 10 Avalon®-MM Interface for PCIe* with DMA example design fail the link test and the DMA test when using the default selected BAR0?DescriptionWhen the internal DMA Descriptor Controller is enabled, the BAR0 Avalon®-MM master is not available for general-purpose usage. The DMA Descriptor Controller uses this BAR0 interface through which the host CPU programs in the descriptor table.
The intel_fpga_pcie_link_test user application selects BAR0 as default when it's initially executed. If the user forgets to change to BAR2, which is where the onchip memory is attached, then both the link test and the DMA test will fail.
ResolutionThe user must change to BAR2 before executing the link test and the DMA test.
See the execution transcript of the intel_fpga_pcie_link_test user application below for how to change to BAR2.
~$ sudo ./intel_fpga_pcie_link_test
*********************************************************
Intel FPGA PCIe Link Test
Version 2.0
0: Automatically select a device
1: Manually select a device
*********************************************************
> 0
Opened a handle to BAR 0 of a device with BDF 0x1300
*********************************************************
0: Link test - 100 writes and reads
1: Write memory space
2: Read memory space
3: Write configuration space
4: Read configuration space
5: Change BAR
6: Change device
7: Enable SRIOV
8: Do a link test for every enabled virtual function
belonging to the current device
9: Perform DMA
10: Quit program
*********************************************************
> 5
Changing BAR...
Enter BAR number (-1 for none):
> 2
Successfully changed BAR!
ContributorYou run the PCIe link test in manual or automatic mode?
— In automatic mode, the application automatically selects the device. The test selects the Intel Stratix 10 PCIe device with the lowest BDF by matching the Vendor ID. The test also selects the lowest available BAR (which is BAR0).
— In manual mode, the test queries you for the bus, device, and function number and BAR.
The other thing you can try is instead of selecting option 0 to automatically select the device, you try option 1 and manually select it.
In manual mode, use below command to determine the BDF.
$ lspci -d 1172
Then, enter the BDF and use BAR 2 for manual test, screenshot below show the manual test steps.
ContributorThe problem you seen might related to below KBD
Why does the Intel® Stratix® 10 Avalon®-MM Interface for PCIe* with DMA example design fail the link test and the DMA test when using the default selected BAR0?
When the internal DMA Descriptor Controller is enabled, the BAR0 Avalon®-MM master is not available for general-purpose usage. The DMA Descriptor Controller uses this BAR0 interface through which the host CPU programs in the descriptor table.
The intel_fpga_pcie_link_test user application selects BAR0 as default when it's initially executed. If the user forgets to change to BAR2, which is where the onchip memory is attached, then both the link test and the DMA test will fail.
The user must change to BAR2 before executing the link test and the DMA test.
See the execution transcript of the intel_fpga_pcie_link_test user application below for how to change to BAR2.
~$ sudo ./intel_fpga_pcie_link_test
*********************************************************
Intel FPGA PCIe Link Test
Version 2.0
0: Automatically select a device
1: Manually select a device
*********************************************************
> 0
Opened a handle to BAR 0 of a device with BDF 0x1300
*********************************************************
0: Link test - 100 writes and reads
1: Write memory space
2: Read memory space
3: Write configuration space
4: Read configuration space
5: Change BAR
6: Change device
7: Enable SRIOV
8: Do a link test for every enabled virtual function
belonging to the current device
9: Perform DMA
10: Quit program
*********************************************************
> 5
Changing BAR...
Enter BAR number (-1 for none):
> 2
Successfully changed BAR!
He4ForumYou are right! This does solve the problem. Thanks!
- He4Forum
Bad news. The method only works for the first time I swicth to BAR2. During the first try, reading and writing operations worked very well.
While I retried and found the same issue occured again though I had tried automatically and manually selecting the device.
It's weird...
- He4Forum
Your method is truely the solution.
However, I have tried several times. It shows the card with DMA feature could work for a while, then there will be something wrong with the card. In Quartus Software->Tools->Programmer, the USB blaster II should always be there. When the DMA could not work, I find that the USB blaster II will disappear. Only using $shutdown command to power the host machine and the card off could make the USB blaster II appear.
