On 4/28/2020 8:54 AM, Dan Carpenter wrote:
>> @@ -897,7 +897,6 @@ static int hidma_probe(struct platform_device *pdev)
>> if (msi)
> ^^^
> This test doesn't work. It will call free hidma_free_msis() if the
> hidma_request_msi() call fails. We should do:
>
> if (msi) {
> rc = hidma_request_msi(dmadev, pdev);
> msi = false;
> }
>
> if (!msi) {
> hidma_ll_setup_irq(dmadev->lldev, false);
> rc = devm_request_irq(&pdev->dev, chirq, hidma_chirq_handler,
> 0, "qcom-hidma", dmadev->lldev);
> if (rc)
> goto uninit;
> }
>
>
Let me clarify how this works. MSI capability is not present on all
platforms. Therefore, this is detected by an ACPI/DTS parameter called
HIDMA_MSI_CAP.
msi = hidma_test_capability(&pdev->dev, HIDMA_MSI_CAP);
Therefore,
1. Code will request MSI capability if it is present.
2. Code will fallback to plain IRQ, if MSI allocation also fails.
I hope this helps.
We need both #1 and #2 to be supported.
