Re: [PATCH v2 5/6] misc: pci_endpoint_test: Do not request or allocate IRQs in probe

Lorenzo Pieralisi
2021-08-03T09:59:38Z

On Tue, Aug 03, 2021 at 01:19:31PM +0530, Kishon Vijay Abraham I wrote:
> Allocation of IRQ vectors and requesting IRQ is done as part of
> PCITEST_SET_IRQTYPE. Do not request or allocate IRQs in probe for
> AM654 and J721E so that the user space test script has better control
> of the devices for which the IRQs are configured. Since certain user
> space scripts could rely on allocation of IRQ vectors during probe,
> remove allocation of IRQs only for TI's K3 platform.
>
> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
> drivers/misc/pci_endpoint_test.c | 19 +++++++++++++------
> 1 file changed, 13 insertions(+), 6 deletions(-)

I don't claim to understand the inner details of the endpoint test
device but it looks like this approach should be redesigned.

I don't believe using devices quirks is the best approach to
expose/remove a feature to userspace, this can soon become
unmaintenable.

Maybe you can elaborate a bit more on what the real issue is please ?

Thanks,
Lorenzo

> diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
> index c7ee34013485..9740f2a0e7cd 100644
> --- a/drivers/misc/pci_endpoint_test.c
> +++ b/drivers/misc/pci_endpoint_test.c
> @@ -79,6 +79,9 @@
> #define PCI_DEVICE_ID_RENESAS_R8A774C0 0x002d
> #define PCI_DEVICE_ID_RENESAS_R8A774E1 0x0025
>
> +#define is_j721e_pci_dev(pdev) \
> + ((pdev)->device == PCI_DEVICE_ID_TI_J721E)
> +
> static DEFINE_IDA(pci_endpoint_test_ida);
>
> #define to_endpoint_test(priv) container_of((priv), struct pci_endpoint_test, \
> @@ -810,9 +813,11 @@ static int pci_endpoint_test_probe(struct pci_dev *pdev,
>
> pci_set_master(pdev);
>
> - if (!pci_endpoint_test_alloc_irq_vectors(test, irq_type)) {
> - err = -EINVAL;
> - goto err_disable_irq;
> + if (!(is_am654_pci_dev(pdev) || is_j721e_pci_dev(pdev))) {
> + if (!pci_endpoint_test_alloc_irq_vectors(test, irq_type)) {
> + err = -EINVAL;
> + goto err_disable_irq;
> + }
> }
>
> for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) {
> @@ -850,9 +855,11 @@ static int pci_endpoint_test_probe(struct pci_dev *pdev,
> goto err_ida_remove;
> }
>
> - if (!pci_endpoint_test_request_irq(test)) {
> - err = -EINVAL;
> - goto err_kfree_test_name;
> + if (!(is_am654_pci_dev(pdev) || is_j721e_pci_dev(pdev))) {
> + if (!pci_endpoint_test_request_irq(test)) {
> + err = -EINVAL;
> + goto err_kfree_test_name;
> + }
> }
>
> misc_device = &test->miscdev;
> --
> 2.17.1
>