常见问题

dmatest 时 verify 数据报错

现象

当运行 dmatest 测试时，错误 log 类似如下：

[  381.878419] dmatest: dma0chan5-copy0: dstbuf[0x3f70] mismatch! Expected cf, got d7
[  381.885999] dmatest: dma0chan5-copy0: dstbuf[0x3f71] mismatch! Expected ce, got d6
[  381.893611] dmatest: dma0chan5-copy0: dstbuf[0x3f72] mismatch! Expected cd, got d5
[  381.901199] dmatest: dma0chan5-copy0: dstbuf[0x3f73] mismatch! Expected cc, got d4
[  381.908783] dmatest: dma0chan5-copy0: dstbuf[0x3f74] mismatch! Expected cb, got d3
[  381.916350] dmatest: dma0chan5-copy0: dstbuf[0x3f75] mismatch! Expected ca, got d2

原因分析

dmatest 的默认配置是需要 verify 测试数据的。

当进行多通道（max_channels>1）测试时，必须要使能 polled 属性，以保证通道的测试过程是串行的，否则会报 verify 错误。

设置 polled 属性的方法见 dmatest 测试。