Re: [PATCH v9 5/5] usb: dwc3: core: cleanup IRQ resources

[Grygorii Strashko <grygorii.strashko@ti.com>]

On 06/07/2016 12:34 PM, Roger Quadros wrote:
> On 02/06/16 14:52, Grygorii Strashko wrote:
>> On 06/01/2016 10:46 AM, Roger Quadros wrote:
>>> Implementations might use different IRQs for
>>> host, gadget and OTG so use named interrupt resources
>>> to allow Device tree to specify the 3 interrupts.
>>>
>>> Following are the interrupt names
>>>
>>> Peripheral Interrupt - peripheral
>>> HOST Interrupt - host
>>> OTG Interrupt - otg
>>
>> or "dwc_usb3"??
> 
> That is for backward compatibility only. I could explicitly
> mention it in the next line.

yes pls, this confuses.
 Also I don't see how "otg" irq name is used in code.

> 
>>
>>>
>>> We still maintain backward compatibility for a single named
>>> interrupt for all 3 interrupts (e.g. for dwc3-pci) and
>>> single unnamed interrupt for all 3 interrupts (e.g. old DT).
>>
>> bindings
> 
> OK.
>>
>>>
>>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>>> ---
>>> v9: rebased on top of balbi/testing/next
>>>
>>>    drivers/usb/dwc3/core.c   | 10 ----------
>>>    drivers/usb/dwc3/gadget.c | 20 ++++++++++++++++++--
>>>    drivers/usb/dwc3/host.c   | 19 +++++++++++++++++++
>>>    3 files changed, 37 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>>> index 9c4e1d8d..5cedf3d 100644
>>> --- a/drivers/usb/dwc3/core.c
>>> +++ b/drivers/usb/dwc3/core.c
>>> @@ -843,16 +843,6 @@ static int dwc3_probe(struct platform_device *pdev)
>>>        dwc->mem = mem;
>>>        dwc->dev = dev;
>>>
>>> -    res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
>>> -    if (!res) {
>>> -        dev_err(dev, "missing IRQ\n");
>>> -        return -ENODEV;
>>> -    }
>>> -    dwc->xhci_resources[1].start = res->start;
>>> -    dwc->xhci_resources[1].end = res->end;
>>> -    dwc->xhci_resources[1].flags = res->flags;
>>> -    dwc->xhci_resources[1].name = res->name;
>>> -
>>>        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>>        if (!res) {
>>>            dev_err(dev, "missing memory resource\n");
>>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>>> index c37168d..c18c72f 100644
>>> --- a/drivers/usb/dwc3/gadget.c
>>> +++ b/drivers/usb/dwc3/gadget.c
>>> @@ -1726,7 +1726,7 @@ static int dwc3_gadget_start(struct usb_gadget *g,
>>>        int            ret = 0;
>>>        int            irq;
>>>
>>> -    irq = platform_get_irq(to_platform_device(dwc->dev), 0);
>>> +    irq = dwc->irq_gadget;
>>>        ret = request_threaded_irq(irq, dwc3_interrupt, dwc3_thread_interrupt,
>>>                IRQF_SHARED, "dwc3", dwc->ev_buf);
>>>        if (ret) {
>>> @@ -1734,7 +1734,6 @@ static int dwc3_gadget_start(struct usb_gadget *g,
>>>                    irq, ret);
>>>            goto err0;
>>>        }
>>> -    dwc->irq_gadget = irq;
>>>
>>>        spin_lock_irqsave(&dwc->lock, flags);
>>>        if (dwc->gadget_driver) {
>>> @@ -2853,6 +2852,23 @@ static irqreturn_t dwc3_interrupt(int irq, void *_evt)
>>>    int dwc3_gadget_init(struct dwc3 *dwc)
>>>    {
>>>        int                    ret;
>>> +    struct resource *res;
>>> +    struct platform_device *dwc3_pdev = to_platform_device(dwc->dev);
>>> +
>>> +    dwc->irq_gadget = platform_get_irq_byname(dwc3_pdev, "peripheral");
>>> +    if (dwc->irq_gadget <= 0) {
>>
>> Is it expected to get -EPROBE_DEFER here?
> 
> Probably not as we don't have any chance of deferring probe here. We've already
> probed successfully and are just turning on the gadget mode here.

In general, you can't say that you've been probed successfully if not all resources are ready,
and irq is a resource :)
It's expected that all resources will be requested in probe, but here you are trying to get
resource outside of probe. As result, it will be perfectly possible to get -EPROBE_DEFER here
if on some HW GPIO IRQ will be used as peripheral, or host or otg irq (for example), because 
GPIO IRQ controller might not be ready at the moment when IRQ resource is requested.

> 
>>
>>> +        dwc->irq_gadget = platform_get_irq_byname(dwc3_pdev,
>>> +                              "dwc_usb3");
>>> +        if (dwc->irq_gadget <= 0) {
>>> +            res = platform_get_resource(dwc3_pdev, IORESOURCE_IRQ,
>>> +                            0);
>>
>> It's better to use platform_get_irq().
> 
> OK.
>>
>>> +            if (!res) {
>>> +                dev_err(dwc->dev, "missing peripheral IRQ\n");
>>> +                return -ENODEV;
>>> +            }
>>> +            dwc->irq_gadget = res->start;
>>> +        }
>>> +    }
>>>
>>>        dwc->ctrl_req = dma_alloc_coherent(dwc->dev, sizeof(*dwc->ctrl_req),
>>>                &dwc->ctrl_req_addr, GFP_KERNEL);
>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
>>> index c679f63..f2b60a4 100644
>>> --- a/drivers/usb/dwc3/host.c
>>> +++ b/drivers/usb/dwc3/host.c
>>> @@ -25,6 +25,25 @@ int dwc3_host_init(struct dwc3 *dwc)
>>>        struct platform_device    *xhci;
>>>        struct usb_xhci_pdata    pdata;
>>>        int            ret;
>>> +    struct resource        *res;
>>> +    struct platform_device    *dwc3_pdev = to_platform_device(dwc->dev);
>>> +
>>> +    res = platform_get_resource_byname(dwc3_pdev, IORESOURCE_IRQ, "host");
>>> +    if (!res) {
>>> +        res = platform_get_resource_byname(dwc3_pdev, IORESOURCE_IRQ,
>>> +                           "dwc_usb3");
>>> +        if (!res) {
>>> +            res = platform_get_resource(dwc3_pdev, IORESOURCE_IRQ,
>>> +                            0);
>>> +            if (!res)
>>
>>> +                return -ENOMEM;
>>> +        }
>>> +    }
>>
>> Is it expected to have more than one IRQ here?
> 
> No.
>>
>> if not - it will better to use platform_get_irq[_byname]().
> 
> OK.
>>
>>
>>> +
>>> +    dwc->xhci_resources[1].start = res->start;
>>> +    dwc->xhci_resources[1].end = res->end;
>>> +    dwc->xhci_resources[1].flags = res->flags;
>>> +    dwc->xhci_resources[1].name = res->name;
>>>
>>>        xhci = platform_device_alloc("xhci-hcd", PLATFORM_DEVID_AUTO);
>>>        if (!xhci) {
>>>
>>
>>
> 
> cheers,
> -roger
> 


-- 
regards,
-grygorii