Question

我将uio通用驱动程序与由连接到Intel ATOM cpu的PCIe设备（FPGA）组成的硬件一起使用。

但是，在测试中，尽管在驱动程序中看到了中断，但并未将其传递给用户空间。

这些是我正在执行的步骤：

echo "10ee 0007" > /sys/bus/pci/drivers/uio_pci_generic/new_id

我使用等待中断的用户空间应用程序，如代码示例here中所述。

我比从FPGA触发了一个中断，但是没有提供用户空间应用程序的打印，并且有一个例外：

irq 23: nobody cared (try booting with the "irqpoll" option)
[ 91.030760] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.18.16 #6
[ 91.037037] Hardware name: /conga-MA5, BIOS MA50R000 10/30/2019
[ 91.043302] Call Trace:
[ 91.045881] <IRQ>
[ 91.048002] dump_stack+0x5c/0x80
[ 91.051464] __report_bad_irq+0x35/0xaf
[ 91.055465] note_interrupt.cold.9+0xa/0x63
[ 91.059823] handle_irq_event_percpu+0x68/0x70
[ 91.064470] handle_irq_event+0x37/0x57
[ 91.068481] handle_fasteoi_irq+0x97/0x150
...
[ 91.176043] handlers:
[ 91.178419] [<00000000ec05b056>] uio_interrupt
[ 91.183054] Disabling IRQ #23

我开始调试uio驱动程序，并且看到调用了中断处理程序，但未处理：

static irqreturn_t irqhandler(int irq, struct uio_info *info)
{
        struct uio_pci_generic_dev *gdev = to_uio_pci_generic_dev(info);
printk("here 1\n");    <<--- we get here interrupt is catched here
        if (!pci_check_and_mask_intx(gdev->pdev))
                return IRQ_NONE;
printk("here 2\n");    <<--- But we never get here
        /* UIO core will signal the user process. */
        return IRQ_HANDLED;
}

似乎pci_check_and_mask_intx()并未将其检测为来自我们设备的中断！

设备显示如下：

02:00.0 RAM memory: Xilinx Corporation Default PCIe endpoint ID
        Subsystem: Xilinx Corporation Default PCIe endpoint ID
        Control: I/O- Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Interrupt: pin A routed to IRQ 23
        Region 0: Memory at 91200000 (32-bit, non-prefetchable) [size=1M]
        Capabilities: [40] Power Management version 3
                Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
                Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
        Capabilities: [48] MSI: Enable- Count=1/1 Maskable- 64bit+
                Address: 0000000000000000  Data: 0000
        Capabilities: [58] Express (v1) Endpoint, MSI 00
                DevCap: MaxPayload 256 bytes, PhantFunc 1, Latency L0s <64ns, L1 <1us
                        ExtTag+ AttnBtn- AttnInd- PwrInd- RBE+ FLReset- SlotPowerLimit 10.000W
                DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
                        RlxdOrd+ ExtTag+ PhantFunc- AuxPwr- NoSnoop+
                        MaxPayload 256 bytes, MaxReadReq 512 bytes
                DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr- TransPend-
                LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s, Exit Latency L0s unlimited
                        ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp-
                LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- CommClk+
                        ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
                LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
        Capabilities: [100 v1] Device Serial Number 00-00-00-00-00-00-00-00
        Kernel driver in use: uio_pci_generic

这是FPGA设备的问题吗？还是UIO通用PCI不支持中断？

Answer 1

最终在为irqhandler注释了以下各行之后，

我能够从FPGA接收中断

[[

但是，显然，这仍然是一种解决方法，我们稍后需要调查为什么FPGA不能在irq的PCIe配置空间中的状态寄存器中传递位状态更改。

UIO通用PCI是否支持中断？

1 个答案: