Re: [PATCH v3 02/26] PCI: keystone: Cleanup error_irq configuration

Kishon Vijay Abraham I
2019-04-15T05:29:55Z

Hi Bjorn,

On 13/04/19 7:33 PM, Bjorn Helgaas wrote:
> Hi Kishon,
>
> On Mon, Mar 25, 2019 at 03:09:23PM +0530, Kishon Vijay Abraham I wrote:
>> pci-keystone driver uses irq_of_parse_and_map to get irq number of
>> error_irq. Use platform_get_irq instead and move platform_get_irq()
>> and request_irq() of error_irq from ks_pcie_add_pcie_port to ks_pcie_probe
>> since error_irq is common to both RC mode and EP mode.
>
> Does this have any DT implications?

No. platform_get_irq() uses of_irq_get(), which in-turn uses of_irq_parse_one()
and irq_create_of_mapping() while irq_of_parse_and_map() directly uses
of_irq_parse_one() and irq_create_of_mapping().

The only difference is platform_get_irq() falls back to using
platform_get_resource() if of_irq_get fails.

I thought it's better to use platform_get_irq() for platform devices.

Thanks
Kishon

>
> It's not obvious that platform_get_irq() and irq_of_parse_and_map() work
> similarly or that they get the same result from DT.
>
> I'm sure they *do*, but it would be nice to have some hints in the commit
> log about why that's the case.
>
>> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
>> ---
>> drivers/pci/controller/dwc/pci-keystone.c | 43 +++++++++--------------
>> 1 file changed, 17 insertions(+), 26 deletions(-)
>>
>> diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
>> index 07f55b355d75..e50f8773e768 100644
>> --- a/drivers/pci/controller/dwc/pci-keystone.c
>> +++ b/drivers/pci/controller/dwc/pci-keystone.c
>> @@ -98,8 +98,6 @@ struct keystone_pcie {
>> struct irq_domain *legacy_irq_domain;
>> struct device_node *np;
>>
>> - int error_irq;
>> -
>> /* Application register space */
>> void __iomem *va_app_base; /* DT 1st resource */
>> struct resource app;
>> @@ -743,12 +741,6 @@ static int ks_pcie_config_legacy_irq(struct keystone_pcie *ks_pcie)
>> return ret;
>> }
>>
>> -static void ks_pcie_setup_interrupts(struct keystone_pcie *ks_pcie)
>> -{
>> - if (ks_pcie->error_irq > 0)
>> - ks_pcie_enable_error_irq(ks_pcie);
>> -}
>> -
>> /*
>> * When a PCI device does not exist during config cycles, keystone host gets a
>> * bus error instead of returning 0xffffffff. This handler always returns 0
>> @@ -810,7 +802,6 @@ static int __init ks_pcie_host_init(struct pcie_port *pp)
>>
>> ks_pcie_stop_link(pci);
>> ks_pcie_setup_rc_app_regs(ks_pcie);
>> - ks_pcie_setup_interrupts(ks_pcie);
>> writew(PCI_IO_RANGE_TYPE_32 | (PCI_IO_RANGE_TYPE_32 << 8),
>> pci->dbi_base + PCI_IO_BASE);
>>
>> @@ -854,23 +845,6 @@ static int __init ks_pcie_add_pcie_port(struct keystone_pcie *ks_pcie,
>> struct device *dev = &pdev->dev;
>> int ret;
>>
>> - /*
>> - * Index 0 is the platform interrupt for error interrupt
>> - * from RC. This is optional.
>> - */
>> - ks_pcie->error_irq = irq_of_parse_and_map(ks_pcie->np, 0);
>> - if (ks_pcie->error_irq <= 0)
>> - dev_info(dev, "no error IRQ defined\n");
>> - else {
>> - ret = request_irq(ks_pcie->error_irq, ks_pcie_err_irq_handler,
>> - IRQF_SHARED, "pcie-error-irq", ks_pcie);
>> - if (ret < 0) {
>> - dev_err(dev, "failed to request error IRQ %d\n",
>> - ks_pcie->error_irq);
>> - return ret;
>> - }
>> - }
>> -
>> pp->ops = &ks_pcie_host_ops;
>> ret = ks_pcie_dw_host_init(ks_pcie);
>> if (ret) {
>> @@ -946,6 +920,7 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
>> u32 num_lanes;
>> char name[10];
>> int ret;
>> + int irq;
>> int i;
>>
>> ks_pcie = devm_kzalloc(dev, sizeof(*ks_pcie), GFP_KERNEL);
>> @@ -965,6 +940,20 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
>> return ret;
>> }
>>
>> + irq = platform_get_irq(pdev, 0);
>> + if (irq < 0) {
>> + dev_err(dev, "missing IRQ resource: %d\n", irq);
>> + return irq;
>> + }
>> +
>> + ret = request_irq(irq, ks_pcie_err_irq_handler, IRQF_SHARED,
>> + "ks-pcie-error-irq", ks_pcie);
>> + if (ret < 0) {
>> + dev_err(dev, "failed to request error IRQ %d\n",
>> + irq);
>> + return ret;
>> + }
>> +
>> ret = of_property_read_u32(np, "num-lanes", &num_lanes);
>> if (ret)
>> num_lanes = 1;
>> @@ -1020,6 +1009,8 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
>> if (ret < 0)
>> goto err_get_sync;
>>
>> + ks_pcie_enable_error_irq(ks_pcie);
>> +
>> return 0;
>>
>> err_get_sync:
>> --
>> 2.17.1
>>