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Altera_Forum
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9 years ago

altera_dma driver for PCIe

Hi everyone, i'm using an Arria V starter kit for PCIe application and i used the reference design posted in altera wiki. The application software reported success in one PC but not in other with dif...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
9 years ago

I am encountering the same problem, in which my DMA read and writes always time out. 


************************************************ ALTERA AVMM DMA driver                   **
** version 2.02                              **
** 1) start DMA                             **
** 2) enable/disable read dma               **
** 3) enable/disable write dma              **
** 4) enable/disable simul dma              **
** 5) set num dwords (256 - 2048)           **
** 6) set num descriptors (1 - 128)         **
** 8) loop dma                              **
** 10) exit                                 **
**********************************************
Run Read                ? 1
Run Write               ? 1
Run Simultaneous        ? 1
Read Passed             ? 0
Write Passed            ? 0
Simultaneous Passed     ? 0
Read EPLast timeout     ? 1
Write EPLast timeout    ? 1
Number of Dwords/Desc   : 512
Number of Descriptors   : 128
Length of transfer      : 256 KB
Rootport address offset : 0
Read Time               : 1 s and 227400 us
Read Throughput         : 0.000199 GB/S
Write Time              : 1 s and 230367 us
Write Throughput        : 0.000198 GB/S
Simultaneous Time       : 1 s and 238158 us
Simultaneous Throughput : 0.000394 GB/S

When I tried the burst mode (loop dma), I got 

#  DMA data error!
Type in dmesg to show more details!

And by checking dmesg I got the following 


 Read DMA times out
 DWORD = 00000100
 Desc = 00000080
 Read DMA times out
 DWORD = 00000100
 Desc = 00000080
 Read DMA times out
 DWORD = 00000100
 Desc = 00000080
 Read DMA times out
 DWORD = 00000100
 Desc = 00000080
 Read DMA times out
 DWORD = 00000200
 Desc = 00000080
 Write DMA times out
 DWORD = 00000200
 Desc = 00000080
 Simultaneous DMA times out
 DWORD = 00000200
 Desc = 00000080
 command issued from user space doesn't exist 2608
 command issued from user space doesn't exist 2608

Does anyone have any clue why this would happen? Any suggestion or hint is much appreciated!