Linux interrupt is not handled by the wrapper driver

Question

I am writing a device specific DMA driver for Zynq AXI DMA. The driver is actually a wrapper driver and uses Xilinx DMA driver under the DMA engine driver framework like this:

+------------------+
  |   Wrapper driver |
  +------------------+
  |   DMA framework  |
  +------------------+
  | Xilinx DMA Driver|
  +------------------+
  +      Kernel      +
  +------------------+

I use interrupt 61 for transfer complete and 62 for receive complete. The interrupt handler for Xilinx DMA driver is properly installed (I checked /proc/interrupts). However, I the driver seems not to handle the interrupt properly by showing me this:

I checked /proc/interrupts. IRQ62 is not handled. Here is the code where the interrupt is registered:

0986     /* find the IRQ line, if it exists in the device tree */
0987     chan->irq = irq_of_parse_and_map(node, 0);
0988     err = devm_request_irq(xdev->dev, chan->irq, dma_intr_handler,
0989                    IRQF_SHARED,
0990                    "xilinx-dma-controller", chan);

And here is the output of cat /proc/interrupt:

I have two questions:

1) If I only install interrupt handler for Xilinx DMA driver but not the wrapper driver, while I use the wrapper driver as the char device, interrupt will not be handled by the Xilinx DMA driver?

2) If so, how do I let Xilinx DMA driver to handle the interrupt in this case? Is 'irqpoll' the only solution? Is there any performance issue compared to direct interrupt handling rather than polling?

Answer 1

Your devicetree isn't good, more precisely, your pl.dtsi file. My pl file looks like this:

amba_pl: amba_pl {
    #address-cells = <1>;
    #size-cells = <1>;
    compatible = "simple-bus";
    ranges ;
    axi_dma_0: dma@40400000 {
        compatible = "xlnx,axi-dma";
        interrupt-parent = <&intc>;
        interrupts = <0 29 4 0 30 4>;
        reg = <0x40400000 0x10000>;
        xlnx,include-sg ;
        dma-channel@40400000 {
            compatible = "xlnx,axi-dma-mm2s-channel";
            interrupts = <0 29 4>;
            xlnx,datawidth = <0x20>;
            xlnx,device-id = <0x0>;
        };
        dma-channel@40400030 {
            compatible = "xlnx,axi-dma-s2mm-channel";
            interrupts = <0 30 4>;
            xlnx,datawidth = <0x20>;
            xlnx,device-id = <0x0>;
        };
    };

};